Toshiba TV29C90 problem; Image fades to black...

[Mike Berger]

Electrically programmed non-volatile memory chips have a finite number
of programming cycles before they start to fail. It's far easier to
replace
a battery every 5 years than to accomodate sudden and subtle failures.

john private smith wrote:

i wondered, WHY!!!!??? did
ge choose to use volitale ram for storing critical information like
config and personality info???? when they could have done like
motorola and used non voliatle ram that does not need a battery? i
donot understand this, the technology has long since been available in
1990 for battery free radio memory to exist.

 

[Fred Abse]

On Sun, 27 Jul 2003 16:28:36 +0100, David Lesher wrote:

I'd say that is highly unlikely in a washing machine. Who/what would
measure the speed?

The speed controller

--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Robert Morein]

I wasn't going to short them.
I was considering discharging them further with a resistor.
However, it appears that further discharge runs the risk of damaging the
cells.
I'm going to skip the project for now, because I don't have a welder.

"Jerry G." <jerryg@total.net> wrote in message
news:bg3pi1$a62$1@news.eusc.inter.net...

DO NOT short or discharge these batteries even when working with them.
Only when shorted or directly across a shorted load are they dangerous.
Discharging these batteries to a low level is not very good for them!
Only their normal amount of discharge during use is acceptable, and they
should be recharged soon after.

Even when these batteries are normally discharged, they can put out
enough current to cause burns, or flame. This is why proper practice is
required when working with these types of batteries.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
==============================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
Instruments http://www.zoom-one.com/glgtech.htm
==============================================
"Robert Morein" <nowhere@nothing.com> wrote in message
news:HLGcnacvmrNNObmiXTWJkw@comcast.com...
I have good cells I can use to refurbish a lithium pack for my Fujitsu
portable.
I have cut open the pack, and can wire in identical replacements.

Since these cells are dangerous, I discharged them to 0% in my laptop.
They still read 9.7V (three 3.6V pairs of cells in series).

I understand that at this level of charge, they are still somewhat
dangerous.
But I've also read that discharging the cells to 0V permanently damages
them.

I would appreciate any specific information available on the correct
level
of discharge for cells which are being handled in the process of
installation.

 

[bg]

The heads from left to right are, the erase head, the record head and the
playback head. Any cassette I've ever seen has a guide attached to the
playback head. If possible, bend the damaged guide back into place. Usually
this guide is spot welded, therefore the height of the guide might not have
changed. This guide sets the tracking which usually is not adjustable
because the guide is fixed to the playback head at the factory. On rare
occasions this guide is adjustable.
The tilt of the head sets azimuth which is adjustable on all decks. You will
have to examine the record and playback heads to see if there is azimuth
adjustments for both heads. I would expect there is. Head height raises or
lowers the position of the head gaps on the tape. Azimuth rotates the gaps
so that they are aligned perpendicular (90 degrees) to the tape. Azimuth
will have a slight effect on the head height. Another head adjustment you
might have is zenith. Usually located at the rear of the head, it tilts the
face of the head, so that the head is parallel to the tape. This adjustment
if incorrect, would tilt the top of the head either closer or further from
the tape than the bottom of the head. It causes uneven head wear and it
causes the tape to scew up and down. As the tape scews, the azimuth and
tracking will also be out of adjustment. The erase head should also have a
non adjustable guide affixed to it.
Check to see that you have these guides in place, the azimuth and zenith
adjustments, and that the adjustments will move the heads. If you can't
physically align the heads, or the guides are bad, there is no sense in
going any further. you will have to replace whatever mechanics are bad.
You might want to sacrafice an old cassette by cutting away the plastic
shell in the area where the heads contact the tape. This will give you the
abiltiy to see how the tape rides over the heads. If the tape is visibly
moving up or down, you will have to correct this. It is impossible to align
a head to tape that moves all over the place. The basic concept is to set
all guides at the same height so that the tape enters the shell and leaves
the shell at the same height. Any guides in between should not raise or
lower the tape as it travels thru the shell.
Post back here with your results and we'll determine the next step.
bg


Marko wrote in message ...

BG: I thought I would check for replies just one more time before I
stopped
NG activity for awhile. Glad I did.


I have a signal generator, alignment tape, scope, and HP5210 freq meter
that
I have used to set the motor RPM with 1KHz test tone.

I haven't checked yet, but I am hoping that

(1) the head on the far right is the play head
(2) the tape monitor switch will allow me to record a test tone (I will use
10KHz) and then monitor it with the play head so that I can align the
record
head.
(3) that the tape guide on the PB head (which has been bent out of the tape
path) is not necessary for proper tape transfer over the heads.

What worries me is that the tape guide is on the record head and I must
align the playback head first.

I didn't notice the third head at first and aligned the playback with the
record head adjustment screw. This worked because the tape guide is on the
record head.

How do I start out with proper alignment of the two tape guides before
aligning the heads? One guide, the first one, is affixed to the transport
frame and the second guide is affixed to the record head. I think this
problem may have been encountered by
whoever worked on it before it was sent to a resale shop. I could see that
they had disturbed the paint on the screws. It also had two stretched
belts
and a very dirty rec/play switch on the board, so I'm not sure. The belts
may have stretched and the grease in the switch may have dried from sitting
on the shelf for years after they encountered the alignment problem.

What do you suggest? Sincerely, Mark (this is a top post)






----- Original Message -----
From: "bg" <bg@nospam.com
Newsgroups: sci.electronics.repair
Sent: Sunday, July 27, 2003 11:46 PM
Subject: Re: Fisher cassette heads


You need an audio generator, and an AC audio voltmeter with a DB scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way. The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark





"bg" <bg@nospam.com> wrote in message
news:bg29k2$6ia$1@terabinaries.xmission.com...
You need an audio generator, and an AC audio voltmeter with a DB scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way. The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark

 

[cablespec@3web.net]

cablespec@3web.net (cablespec@3web.net) wrote in message news:<b8b7ae38.0307271850.4bf11867@posting.google.com>...

Hello,

I have got a TEAC CD-Z500 (esoteric) compact disc player that refuse
to play. It stops working during the play back repeating mode (playing
same track during 1 hour).


When I insert a CD in the tray :

1- the drawer closes perfectely ... no problem,
2- there are no interlock switch on this model
3- the pickup assembly reset to the starting point to the inner center
track of disc with no problem,
3a- the laser beam goes on for 4 sec and shut down
4- the laser pickup assembly move freely and smoothly on the track,
5- THE PICKUP LASER DO NOT FOCUS AT ALL WITH OR WITHOUT A DISC (CD),
6- NO RED SPOT WHEN I VIEW THE LENS FROM AN OBLIQUE ANGLE DURING FOCUS
SEARCH
7- NO SPINNING MOTOR ACTION

I checked the following:

1- I clean the lens,
2- no broken or damaged gear theeth anywhere,
3- the drawer close completely and freely,
4- the (path) track is clean and freely,
5- all flat cables and connectors OK,
6- sloder joints OK
6- my CD (disc) is clean with no scratch on it
7- power transformer seem very hot but everything light (display,
motor tray OK),
8- the DACs (2x) on the audio PCB (at left of the pickup) runs hot
9- voltage according to regulators (7805, 7905, 7815 = OK)


There are the following parts in the servo control:

STA341M IC motor P/N array driver
NJM4565L ???
LA6500 regulators (no info ??? on voltage output in the power supply
section).

I checked all transistors and resistors including low resistors values
= everything looks OK!
There is an optical sensor under the laser pickup assembly,
and the laser pickup part number is a Sony number KSS150. Funny
thing, all parts on the PCB board are SONY! (pcb located right of the
picup assembly)

No service manual, schematic, or data info ..service manual is 85$$
too expensive for me. TEAC customer service is really bad!

Anybody knows this model and trouble associated ... someone can help
me ...

Thanks a lot!

Mike
cablespec@3web.net

 

[Bill Jr]

Nigel,
Thanks for the smile.
I really needed it today.

Cheers,
Bill Jr


"Nigel" <Nigel@nospam.com> wrote in message
news:K19Va.7894$9f7.917908@news02.tsnz.net...

Mid-life crisis time !

Maybe this article from 1999 by the late Douglas Adams, will sooth your
troubled mind - and raise a smile.

http://www.douglasadams.com/dna/19990901-00-a.html


This piece first appeared in the News Review section of The Sunday Times
on
August 29th 1999.

A couple of years or so ago I was a guest on Start The Week, and I was
authoritatively informed by a very distinguished journalist that the whole
Internet thing was just a silly fad like ham radio in the fifties, and
that
if I thought any different I was really a bit naďve. It is a very British
trait - natural, perhaps, for a country which has lost an empire and found
Mr Blobby - to be so suspicious of change.

But the change is real. I don't think anybody would argue now that the
Internet isn't becoming a major factor in our lives. However, it's very
new
to us. Newsreaders still feel it is worth a special and rather worrying
mention if, for instance, a crime was planned by people 'over the
Internet.'
They don't bother to mention when criminals use the telephone or the M4,
or
discuss their dastardly plans 'over a cup of tea,' though each of these
was
new and controversial in their day.

Then there's the peculiar way in which certain BBC presenters and
journalists (yes, Humphrys Snr., I'm looking at you) pronounce internet
addresses. It goes 'www DOT . bbc DOT. co DOT. uk SLASH. today SLASH.'
etc.,
and carries the implication that they have no idea what any of this
new-fangled stuff is about, but that you lot out there will probably know
what it means.

I suppose earlier generations had to sit through all this huffing and
puffing with the invention of television, the phone, cinema, radio, the
car,
the bicycle, printing, the wheel and so on, but you would think we would
learn the way these things work, which is this:

1) everything that's already in the world when you're born is just normal;

2) anything that gets invented between then and before you turn thirty is
incredibly exciting and creative and with any luck you can make a career
out
of it;

3) anything that gets invented after you're thirty is against the natural
order of things and the beginning of the end of civilisation as we know it
until it's been around for about ten years when it gradually turns out to
be
alright really.

Apply this list to movies, rock music, word processors and mobile phones
to
work out how old you are.

This subjective view plays odd tricks on us, of course. For instance,
'interactivity' is one of those neologisms that Mr Humphrys likes to
dangle
between a pair of verbal tweezers, but the reason we suddenly need such a
word is that during this century we have for the first time been dominated
by non-interactive forms of entertainment: cinema, radio, recorded music
and
television. Before they came along all entertainment was interactive:
theatre, music, sport - the performers and audience were there together,
and
even a respectfully silent audience exerted a powerful shaping presence on
the unfolding of whatever drama they were there for. We didn't need a
special word for interactivity in the same way that we don't (yet) need a
special word for people with only one head.

I expect that history will show 'normal' mainstream twentieth century
media
to be the aberration in all this. 'Please, miss, you mean they could only
just sit there and watch? They couldn't do anything? Didn't everybody feel
terribly isolated or alienated or ignored?'

'Yes, child, that's why they all went mad. Before the Restoration.'

'What was the Restoration again, please, miss?'

'The end of the twentieth century, child. When we started to get
interactivity back.'

Because the Internet is so new we still don't really understand what it
is.
We mistake it for a type of publishing or broadcasting, because that's
what
we're used to. So people complain that there's a lot of rubbish online, or
that it's dominated by Americans, or that you can't necessarily trust what
you read on the web. Imagine trying to apply any of those criticisms to
what
you hear on the telephone. Of course you can't 'trust' what people tell
you
on the web anymore than you can 'trust' what people tell you on
megaphones,
postcards or in restaurants. Working out the social politics of who you
can
trust and why is, quite literally, what a very large part of our brain has
evolved to do. For some batty reason we turn off this natural scepticism
when we see things in any medium which require a lot of work or resources
to
work in, or in which we can't easily answer back - like newspapers,
television or granite. Hence 'carved in stone.' What should concern us is
not that we can't take what we read on the internet on trust - of course
you
can't, it's just people talking - but that we ever got into the dangerous
habit of believing what we read in the newspapers or saw on the TV - a
mistake that no one who has met an actual journalist would ever make. One
of
the most important things you learn from the internet is that there is no
'them' out there. It's just an awful lot of 'us'.

Of course, there's a great deal wrong with the Internet. For one thing,
only
a minute proportion of the world's population is so far connected. I
recently heard some pundit on the radio arguing that the internet would
always be just another unbridgeable gulf between the rich and the poor for
the following reasons - that computers would always be expensive in
themselves, that you had to buy lots of extras like modems, and you had to
keep upgrading your software. The list sounds impressive but doesn't stand
up to a moment's scrutiny. The cost of powerful computers, which used to
be
around the level of jet aircraft, is now down amongst the colour
television
sets and still dropping like a stone. Modems these days are mostly
built-in,
and standalone models have become such cheap commodities that companies,
like Hayes, whose sole business was manufacturing them are beginning to go
bust.. Internet software from Microsoft or Netscape is famously free.
Phone
charges in the UK are still high but dropping. In the US local calls are
free. In other words the cost of connection is rapidly approaching zero,
and
for a very simple reason: the value of the web increases with every single
additional person who joins it. It's in everybody's interest for costs to
keep dropping closer and closer to nothing until every last person on the
planet is connected.

Another problem with the net is that it's still 'technology', and
'technology', as the computer scientist Bran Ferren memorably defined it,
is
'stuff that doesn't work yet.' We no longer think of chairs as technology,
we just think of them as chairs. But there was a time when we hadn't
worked
out how many legs chairs should have, how tall they should be, and they
would often 'crash' when we tried to use them. Before long, computers will
be as trivial and plentiful as chairs (and a couple of decades or so after
that, as sheets of paper or grains of sand) and we will cease to be aware
of
the things. In fact I'm sure we will look back on this last decade and
wonder how we could ever have mistaken what we were doing with them for
'productivity.'

But the biggest problem is that we are still the first generation of
users,
and for all that we may have invented the net, we still don't really get
it.
In 'The Language Instinct', Stephen Pinker explains the generational
difference between pidgin and creole languages. A pidgin language is what
you get when you put together a bunch of people - typically slaves - who
have already grown up with their own language but don't know each others'.
They manage to cobble together a rough and ready lingo made up of bits of
each. It lets them get on with things, but has almost no grammatical
structure at all.

However, the first generation of children born to the community takes
these
fractured lumps of language and transforms them into something new, with a
rich and organic grammar and vocabulary, which is what we call a Creole.
Grammar is just a natural function of children's brains, and they apply it
to whatever they find.

The same thing is happening in communication technology. Most of us are
stumbling along in a kind of pidgin version of it, squinting myopically at
things the size of fridges on our desks, not quite understanding where
email
goes, and cursing at the beeps of mobile phones. Our children, however,
are
doing something completely different. Risto Linturi, research fellow of
the
Helsinki Telephone Corporation, quoted in Wired magazine, describes the
extraordinary behaviour kids in the streets of Helsinki, all carrying
cellphones with messaging capabilities. They are not exchanging important
business information, they're just chattering, staying in touch. "We are
herd animals," he says. "These kids are connected to their herd - they
always know where it's moving." Pervasive wireless communication, he
believes will "bring us back to behaviour patterns that were natural to us
and destroy behaviour patterns that were brought about by the limitations
of
technology."

We are natural villagers. For most of mankind's history we have lived in
very small communities in which we knew everybody and everybody knew us.
But
gradually there grew to be far too many of us, and our communities became
too large and disparate for us to be able to feel a part of them, and our
technologies were unequal to the task of drawing us together. But that is
changing.

Interactivity. Many-to-many communications. Pervasive networking. These
are
cumbersome new terms for elements in our lives so fundamental that, before
we lost them, we didn't even know to have names for them.


"Doug Taylor" <techno2nospam@videotron.ca> wrote in message
news:slrnbho2vf.ll.techno2nospam@localhost.localdomain...

Imagine if you bought a car for $30,000 and in 1 year it
was worth $15,000 and in 2 years it was valued at $5,000.
That's exactly what happens in the world of computers today.
You buy a new system for $3,000 and in 2 years it's worth
$500. and in three it's a worthless antique.

How can people be expected to cope and understand this model
of economics for computers.
They cannot understand paying $3000. on their credit card for
a consumer electronic item and have it valued at nothing before
they have finished paying for it.

Such is one of the disadvantages of such horrendous technological
advances and rapid change.
How many times have you been approached by a person with a 3 year
old computer and asked if you can upgrade it so the person
can do Video over the Net etc.
When you try to explain that they have to scrap the system and buy
a new one that's much more powerful, they ask you :
"How much can I get for my old system"
Of couse you don't have the heart to tell them the truth and so
you answer "I don't know" and walk away.

I say give me back the old days of vacuum tubes and Black and White
TV's.
At least they would last you 20 years before needing replacement. 8*)
Maybe need a few tubes once in a while. 8*0

Ah! I guess I'm being unrealistic, and must get back to the program
of instant obsolescence, and constant consumerism.
Hey Joe!
"Let's make the stuff outdated & break before they get it home."

Or how about doing the "Missiom Impossible" stunt and make the
stuff self destruct after 3 years. 8*)
Maybe I'm being too negative.....
Polly Anna where are you ....


--
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
D E A D O N A R R I V A L

B B S

telnet://doabbs.dynip.com http://www.dsuper.net/~techno

 

[Imran]

Mark,

I have been having exactly the same problem. The sound works fine when
I turn off the DSP.
I read you response on two posts and gather that you may have some
expertise on this.
Would you care to share how you came to this conclusion and if you
know of any specific work arounds?

Thanks,
Imran.


"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message news:<2n5Na.24314$C83.2280450@newsread1.prod.itd.earthlink.net>...

Lots of DSP board failures on these. Good luck with that.

Mark Z.


"Sean Piper" <inskipp@shaw.ca> wrote in message
news:BB29CA22.4F0B%inskipp@shaw.ca...
I have a one-year old RCA RT2280 surround system. Yesterday all of a
sudden
it stopped producing sound. I checked all the obvious problems like mute,
cables, speaker connections and so forth but was unable to get it working.
I
made sure the input and output settings were correct and they are. If
anyone
has any ideas about this problem please email kingsnoofer@msn.com. I would
really appreciate any help you can off as I cannot afford to take it in
and
will only do so if absolutely necessary.

Sean

 

[Michael A. Terrell]

Lionel Sharp wrote:

Will make it an expensive repair with the company having an $1000
minimum order policy.

Current Terms and Conditions...

Minimum Order..... $1000 (orders less than $3000 are scheduled for
single release)
Shipping.................. F.O.B. - Tempe, AZ
Packaging............... Standard packaging will be used unless
otherwise specified.

Lionel L Sharp
VK4NS

Michael A. Terrell wrote:
"G. Skiffington" wrote:

Looking for 4 units (or 2 minimum) of this 18 pin dip. Used in the
Yaesu FT767GX, Heathkit HW5400 and likely other equipment - not having
any luck, so far, trying to find a supplier in Canada or the US with
stock. Any leads or help appreciated (I have data).

remove REDUCE to reply



Obsolete, and the rights to manufacture were sold to Lansdale
http://www.lansdale.com/prdmot10.htm

You might get them to tell you who bought a quantity, and buy a
couple from them. I know that Lansdale is hard to deal with. They make
their money on E.O.L. parts to complete contracts. At least SOMEONE is
making replacement parts.
--


Michael A. Terrell
Central Florida

 

[~^Johnny^~]

On Sun, 27 Jul 2003 23:34:11 +0000 (UTC), David Lesher
<wb8foz@panix.com> wrote:

but I've fixed my share
of FSP's [various nameplates]

LOL!

Whirpool, FYI.


"FSP" is Whirlpool's acronym meaning: "Factory Specialized Part".

--
-john


~~~~~~~~
"When the world was flat as a pancake,
Mona Lisa was happy as a clam." - John Prine
~~~~~~~~

 

[Marko]

"bg" <bg@nospam.com> wrote in message
news:bg3s50$qi0$1@terabinaries.xmission.com...

The heads from left to right are, the erase head, the record head and the
playback head. Any cassette I've ever seen has a guide attached to the
playback head.

The guide attached to the PB head is fine. It is the one on the Rec head
that is bent. It is ruined. It was affixed to the R-head with a screw and
enamel. It came loose and is impossible to align. The head must be removed
to tighten the screw and adjustment is not possible when head is remounted.

The deck appears to be technology without due design consideration.


If possible, bend the damaged guide back into place. Usually

this guide is spot welded, therefore the height of the guide might not
have
changed. This guide sets the tracking which usually is not adjustable
because the guide is fixed to the playback head at the factory. On rare
occasions this guide is adjustable.
The tilt of the head sets azimuth which is adjustable on all decks.

As with every other deck i have seen, which are all single motor low end
decks, only the azimuth is adjustable with the typical screw and spring set
up.

You will

have to examine the record and playback heads to see if there is azimuth
adjustments for both heads.

yes, there is also azimuth for the record head

I would expect there is. Head height raises or

lowers the position of the head gaps on the tape.

I will look again to see if there is a height adj

Azimuth rotates the gaps

so that they are aligned perpendicular (90 degrees) to the tape.

I understand

Azimuth

will have a slight effect on the head height. Another head adjustment you
might have is zenith. Usually located at the rear of the head, it tilts
the
face of the head, so that the head is parallel to the tape.

I'll check, I have never noticed this

This adjustment

if incorrect, would tilt the top of the head either closer or further from
the tape than the bottom of the head. It causes uneven head wear and it
causes the tape to scew up and down. As the tape scews, the azimuth and
tracking will also be out of adjustment. The erase head should also have a
non adjustable guide affixed to it.

Yes, it does

Check to see that you have these guides in place, the azimuth and zenith
adjustments, and that the adjustments will move the heads.

It looks to me that the zenith is set with the azimuth screw. There is some
travel in the slot that allows rotation of the head.

If you can't

physically align the heads, or the guides are bad, there is no sense in
going any further. you will have to replace whatever mechanics are bad.
You might want to sacrafice an old cassette by cutting away the plastic
shell in the area where the heads contact the tape. This will give you the
abiltiy to see how the tape rides over the heads.

I will look into it

If the tape is visibly

moving up or down, you will have to correct this. It is impossible to
align
a head to tape that moves all over the place. The basic concept is to set
all guides at the same height so that the tape enters the shell and
leaves
the shell at the same height.

Makes sense

Any guides in between should not raise or

lower the tape as it travels thru the shell.
Post back here with your results and we'll determine the next step.

Thanks BG. I have several projects like this. This one will have to sit
awhile until its' time comes. I wanted to look into it now so I could plan
what to do.

If you will send me your e-mail address to marko@vonl.com I will get back to
you when I get these other projects out of the way.

Sincerely, Mark

bg


Marko wrote in message ...
BG: I thought I would check for replies just one more time before I
stopped
NG activity for awhile. Glad I did.


I have a signal generator, alignment tape, scope, and HP5210 freq meter
that
I have used to set the motor RPM with 1KHz test tone.

I haven't checked yet, but I am hoping that

(1) the head on the far right is the play head
(2) the tape monitor switch will allow me to record a test tone (I will
use
10KHz) and then monitor it with the play head so that I can align the
record
head.
(3) that the tape guide on the PB head (which has been bent out of the
tape
path) is not necessary for proper tape transfer over the heads.

What worries me is that the tape guide is on the record head and I must
align the playback head first.

I didn't notice the third head at first and aligned the playback with the
record head adjustment screw. This worked because the tape guide is on
the
record head.

How do I start out with proper alignment of the two tape guides before
aligning the heads? One guide, the first one, is affixed to the
transport
frame and the second guide is affixed to the record head. I think this
problem may have been encountered by
whoever worked on it before it was sent to a resale shop. I could see
that
they had disturbed the paint on the screws. It also had two stretched
belts
and a very dirty rec/play switch on the board, so I'm not sure. The
belts
may have stretched and the grease in the switch may have dried from
sitting
on the shelf for years after they encountered the alignment problem.

What do you suggest? Sincerely, Mark (this is a top post)






----- Original Message -----
From: "bg" <bg@nospam.com
Newsgroups: sci.electronics.repair
Sent: Sunday, July 27, 2003 11:46 PM
Subject: Re: Fisher cassette heads


You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark





"bg" <bg@nospam.com> wrote in message
news:bg29k2$6ia$1@terabinaries.xmission.com...
You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark

 

[Bruce R. Main]

On Thu, 24 Apr 2003 15:45:21 GMT, "Mike Bates"
<mbates14nospam@nospam.netzero.com> wrote:

they do die like flies. I dont know why.

What I meant by two sides, there are two parts to the DVD/CD laser. There is
a diode for the DVD, and a diode for the CD Two different intensities.
cheaper ones have only one diode, but have two intensities. The laser has to
be much much brighter for a DVD to play, than a CD needs to play. The PS2
was like this, and I seen a cheap RCA portable like this. sometimes, when in
CD mode, youll see a relatively dim beam. and when trying to read a DVD, the
beam gets super bright. Which the intensity that puts out for such a small
diode, is the must likely reason for there failure, but not always.

I didn't know people could see infrared.. There is a small red light
on, but that's just an indicator to tell you NOT TO LOOK at the
laser... and the difference between the cd and dvd laser isn't
intensity, it's size. A dvd laser needs to have a much smaller beam
than a cd player, hence the capacity for higher data density.

What happens upon powerup, or interlock close. is the laser starts out with
a weak beam for CD, and tries to focus, and then it gets bright and tries to
focus. The brightness of the beam lights all of the parts surrounding the
lens. like a laser pointer brightness. then CD brightness is typical.

If when in DVD detecting mode, and the laser is dim, or is not there at all,
but only there on CD, the diode, or driver circuitry is bad.

My 2 cents.

 

[Alex]

3a- the laser beam goes on for 4 sec and shut down

Manually (with power off), guide the sled gear so that the laser pickup
is at the outter edge of the disc. Start the unit and observe.

If the laser diode comes on after the pickup has reset to the inner side,
whilst the laser lens is
ramping up and down, this is normal. Check (with the power off), to make
sure
the spindle motor isnt jammed/sticky. other than that, laser pickups can
still be faulty
even if a glow can be seen from it. Perhaps its intensity/gain is too low
and
it is unable to see the disc. generally, servo faults are not very common.
most
circuitry is pretty robust. Try bending the flexi cable from the pickup just
before
it begins to check for the disc. If the unit springs back to life, then the
problem is pretty obvious.
Continutity tests do not always eliminate the possibility of a flexi cable
being faulty, because it could
going open circuit only on a certain angle.

Sony Pickups are not really of great quality, the newer Sharp pickups have
been the worstly
constructed ones I have ever seen, and they drop like flies. Have a look to
see if the lens has sagged
all the way to the bottom. This is another sign.U can check this by lightly
(very lightly)
pressing on the *side* of the laser lens (with a blunt pointed tool) and see
if it does down
any further. This can cause servo IC's to get hot because it has to
constantly work to keep the lens
at the correct height. Worn motors which are drawing more current than
usual, will cause servo
circuitry to run hot.

I still think your culprit is a flexi cable or laser.

Theres not likely to be a "quick fix" that anyone can suggest, and you say
that
you have cleaned the laser lens, and checked the basic stuff, you're going
to have to start buying parts or at least a service manual.

Alex.

4- the laser pickup assembly move freely and smoothly on the track,
5- THE PICKUP LASER DO NOT FOCUS AT ALL WITH OR WITHOUT A DISC (CD),
6- NO RED SPOT WHEN I VIEW THE LENS FROM AN OBLIQUE ANGLE DURING FOCUS
SEARCH
7- NO SPINNING MOTOR ACTION

I checked the following:

1- I clean the lens,
2- no broken or damaged gear theeth anywhere,
3- the drawer close completely and freely,
4- the (path) track is clean and freely,
5- all flat cables and connectors OK,
6- sloder joints OK
6- my CD (disc) is clean with no scratch on it
7- power transformer seem very hot but everything light (display,
motor tray OK),
8- the DACs (2x) on the audio PCB (at left of the pickup) runs hot
9- voltage according to regulators (7805, 7905, 7815 = OK)


There are the following parts in the servo control:

STA341M IC motor P/N array driver
NJM4565L ???
LA6500 regulators (no info ??? on voltage output in the power supply
section).

I checked all transistors and resistors including low resistors values
= everything looks OK!
There is an optical sensor under the laser pickup assembly,
and the laser pickup part number is a Sony number KSS150. Funny
thing, all parts on the PCB board are SONY! (pcb located right of the
picup assembly)

No service manual, schematic, or data info ..service manual is 85$$
too expensive for me. TEAC customer service is really bad!

Anybody knows this model and trouble associated ... someone can help
me ...

Thanks a lot!

Mike
cablespec@3web.net

 

[Marko]

BG: I have reread your post several times and now realize that without the
guide on the PB head then it is up to me and luck to get it going right.

Unless you have some more advice, thanks much, you've been a great help.
Sincerely, Mark

"bg" <bg@nospam.com> wrote in message
news:bg3s50$qi0$1@terabinaries.xmission.com...

The heads from left to right are, the erase head, the record head and the
playback head. Any cassette I've ever seen has a guide attached to the
playback head. If possible, bend the damaged guide back into place.
Usually
this guide is spot welded, therefore the height of the guide might not
have
changed. This guide sets the tracking which usually is not adjustable
because the guide is fixed to the playback head at the factory. On rare
occasions this guide is adjustable.
The tilt of the head sets azimuth which is adjustable on all decks. You
will
have to examine the record and playback heads to see if there is azimuth
adjustments for both heads. I would expect there is. Head height raises or
lowers the position of the head gaps on the tape. Azimuth rotates the gaps
so that they are aligned perpendicular (90 degrees) to the tape. Azimuth
will have a slight effect on the head height. Another head adjustment you
might have is zenith. Usually located at the rear of the head, it tilts
the
face of the head, so that the head is parallel to the tape. This
adjustment
if incorrect, would tilt the top of the head either closer or further from
the tape than the bottom of the head. It causes uneven head wear and it
causes the tape to scew up and down. As the tape scews, the azimuth and
tracking will also be out of adjustment. The erase head should also have a
non adjustable guide affixed to it.
Check to see that you have these guides in place, the azimuth and zenith
adjustments, and that the adjustments will move the heads. If you can't
physically align the heads, or the guides are bad, there is no sense in
going any further. you will have to replace whatever mechanics are bad.
You might want to sacrafice an old cassette by cutting away the plastic
shell in the area where the heads contact the tape. This will give you the
abiltiy to see how the tape rides over the heads. If the tape is visibly
moving up or down, you will have to correct this. It is impossible to
align
a head to tape that moves all over the place. The basic concept is to set
all guides at the same height so that the tape enters the shell and
leaves
the shell at the same height. Any guides in between should not raise or
lower the tape as it travels thru the shell.
Post back here with your results and we'll determine the next step.
bg


Marko wrote in message ...
BG: I thought I would check for replies just one more time before I
stopped
NG activity for awhile. Glad I did.


I have a signal generator, alignment tape, scope, and HP5210 freq meter
that
I have used to set the motor RPM with 1KHz test tone.

I haven't checked yet, but I am hoping that

(1) the head on the far right is the play head
(2) the tape monitor switch will allow me to record a test tone (I will
use
10KHz) and then monitor it with the play head so that I can align the
record
head.
(3) that the tape guide on the PB head (which has been bent out of the
tape
path) is not necessary for proper tape transfer over the heads.

What worries me is that the tape guide is on the record head and I must
align the playback head first.

I didn't notice the third head at first and aligned the playback with the
record head adjustment screw. This worked because the tape guide is on
the
record head.

How do I start out with proper alignment of the two tape guides before
aligning the heads? One guide, the first one, is affixed to the
transport
frame and the second guide is affixed to the record head. I think this
problem may have been encountered by
whoever worked on it before it was sent to a resale shop. I could see
that
they had disturbed the paint on the screws. It also had two stretched
belts
and a very dirty rec/play switch on the board, so I'm not sure. The
belts
may have stretched and the grease in the switch may have dried from
sitting
on the shelf for years after they encountered the alignment problem.

What do you suggest? Sincerely, Mark (this is a top post)






----- Original Message -----
From: "bg" <bg@nospam.com
Newsgroups: sci.electronics.repair
Sent: Sunday, July 27, 2003 11:46 PM
Subject: Re: Fisher cassette heads


You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark





"bg" <bg@nospam.com> wrote in message
news:bg29k2$6ia$1@terabinaries.xmission.com...
You need an audio generator, and an AC audio voltmeter with a DB
scale.
If
you have this equipment I'll steer you through it.
bg
Marko wrote in message ...
I have a Fisher cassette deck with separate record and playback heads.
I
assume that the one in the middle, the large one, is the record head.

I have a professional alignment tape. How does one align the record
head?
There is a tape monitor switch which probably is used to compare input
to
output.

These are ferrite heads with no visible wear, new belts, switches
cleaned
thoroughly: this deck is worth an alignment as opposed to the trash
can
(mabey).

Also, one tape guide (the one on the far left, just to the left of the
record head) is affixed to the transport frame. The second guide is
affixed
to the record head. The third tape guide on the playback head is bent
over
to the side, obviously bent intentionally to get it out of the way.
The
adjustment screw to this bent guide is not accessable for adjustment
(sloppy
design). The third tape guide is probably not necessary since it is
only
about a cm from the guide on the record head. This transport may be a
piece
of junk due to lousy design.

Any helpful hints will be appreciated Thanks, Mark

 

[Matt Ferrari]

blow it up in a rock video

"No Name" <nomail@nospam.com> wrote in message
news:sgkVa.27683$BM.9052947@newssrv26.news.prodigy.com...

Free for the haul

1986 vintage Mitsubishi Rear Projection TV

Model VS 458R

45"

Wood grain cabinet, with bi-fold doors.

Cabinet is in great shape, tv is dead. Fried yoke.

Call toll free 1-888-584-8117

Bring a big truck and help.

40 mi. southwest of Chicago.

 

[Mark D. Zacharias]

Hello,

I'm not actually an expert on the RT-2280, but I am an authorized RCA
servicer, and I hear stuff and have seen posts on this model before.There
was one servicer who was able to troubleshoot a bad feedthrough connection,
which I would usually be too lazy to bother with.
I would say that the numerous feedthrough connections on the DSP board are
the likely cause of many DSP failures - the physical quality of these boards
doesn't seem too good. Of course the general soldering of the board and it's
connectors should be checked, and one could try resoldering any large IC's -
those surface-mounts sometimes need resoldering.

Mark Z.


"Imran" <aimran50@yahoo.com> wrote in message
news:f7edd128.0307281548.11e69578@posting.google.com...

Mark,

I have been having exactly the same problem. The sound works fine when
I turn off the DSP.
I read you response on two posts and gather that you may have some
expertise on this.
Would you care to share how you came to this conclusion and if you
know of any specific work arounds?

Thanks,
Imran.


"Mark D. Zacharias" <mzacharias@nospam.earthlink.net> wrote in message
news:<2n5Na.24314$C83.2280450@newsread1.prod.itd.earthlink.net>...
Lots of DSP board failures on these. Good luck with that.

Mark Z.


"Sean Piper" <inskipp@shaw.ca> wrote in message
news:BB29CA22.4F0B%inskipp@shaw.ca...
I have a one-year old RCA RT2280 surround system. Yesterday all of a
sudden
it stopped producing sound. I checked all the obvious problems like
mute,
cables, speaker connections and so forth but was unable to get it
working.
I
made sure the input and output settings were correct and they are. If
anyone
has any ideas about this problem please email kingsnoofer@msn.com. I
would
really appreciate any help you can off as I cannot afford to take it
in
and
will only do so if absolutely necessary.

Sean

 

[Charles Schuler]

"Lenny" <captainvideo462002@yahoo.com> wrote in message
news:d980bc2c.0307281750.f8bbfc4@posting.google.com...

My son who works with me in my electronics service business is
presently enrolled in an Electronics Technology course at the local
College. I introduced him to test equipment by getting him a used 260
and a new cheapo hand held digital from Harbor Freight, just so that
he could "get his feet wet". He's a hard worker, and a good boy and
now I would like to do something special for him. He has asked for a
Fluke portable meter with a case for his birthday. Although I own
older model Fluke and HP bench meters, I rarely have a need for them
in my work so with the large selection of new Fluke portables
available frankly I'm stumped as the what is the best deal on a decent
service meter for the money. Thanks for any advice. Lenny Stein.

This looks good to me. No, I don't work for Fluke.

110 Series Features
True-RMS AC voltage and current for accurate readings on all waveforms
6000 count display provides improved resolution
Min/Max/Average recording
Frequency, capacitance & resistance capabilities
112 has a backlight to illuminate the screen in dark workspaces
Easy access battery door to change the battery without breaking the
calibration seal
Drop protected to 1 meter
Holster with probe holders for better test lead management
Compatible with ToolPakT meter hanging kit
Compact & lightweight for use on the go
IEC CAT III 600V safety rating
3-year warranty

 

[Robert Morein]

"Hank" <sorry@nogood.com> wrote in message
news:vfecnWnyOOZ_RLiiXTWJhw@speakeasy.net...

I'd like to put a small but quiet fan right up against the side of the
player so that the player can be tucked back into the entertainment center
and I no longer have to have that relatively large 6" fan propped up on a
box in front of my entertainment center. I'd also like for the fan to be
regular a/c so I can plug it into the switched a/c outlet in my receiver.
Any ideas of what kind of fan to buy and where to buy it (hopefully
relatively inexpensively)?
Thanks,
Hank

P.S. The problem does not lie in its proximity to other heat producing
equipment. I've tried taking it out of the entertainment center with the
cover off and it still overheated. It needs the forced air flow. I'm
trying
to avoid buying a new dvd because it works fine with forced air
ventilation.

This unit doesn't need a fan, it needs a repair.

It's not clear to me whether you want to install a fan that blows through
the player, but that would be a no-go, because the optical mechanism is very
sensitive to dust. It is designed to work only in a dust shielded
environment.

 

[Robert Morein]

"Dave D" <someone@somewhere.com> wrote in message
news:bg5pkk$ab$1@titan.btinternet.com...

"Andre" <testing_h@yahoo.com> wrote in message
news:2c2cf14c.0307290047.a710b01@posting.google.com...
Hi group .

I recently scored a pile of 5V 1W fans . Problem is, for what I want
them for they are too fast, and suck too much current . (200 mA)

I am left with :-

1) Adding a constant current to limit current (and therefore speed)-
easy enough to do . How come there isn't a 100mA "constant current"
diode ?!?!?!
Also I'd need the regulator to drop less than a volt for this to work
.

Put two silicon diodes in series in the 5V supply, works perfectly.


2) Using a lower supply voltage (this would make things worse !)


How? That's exactly what you want to achieve!

3) Using a different fan . (too expensive)

4) Modifying the fan somehow to limit the speed (possible, adding a
capacitor across the Hall sensor output to limit the speed would
likely work but wouldn't solve the current problem)


Are you saying these are speed regulated fans? If so removing the hall
effect sensor might be the first step as they will always attempt to make
up
for your efforts to slow them down. Sometimes (often in PC fans) the hall
effect sensor is there simply to report the rpm to the device it is
connected to.

5) Pulsing the fan voltage so it gets 4V mainly with x % 5V pulses
(this would keep the speed reasonably constant) - anyone done this ?
The idea is to allow the logic to work so fan won't stall, but
limiting the current enough so that it keeps the speed down .


Rather like a sledgehammer to crack a nut! Try the diode idea first.

Dave

In my experience with 12V fans, a series resistor works nicely, as does
running them from a stiff 6V supply.
Unless you have something unusual, these fans do vary RPM in response to
power supply voltage.

You will have to determine the resistor by trial and error, since the fans
do not respond linearly to voltage.

 

[Robert L. Bass]

when i lived in the desert we used to call god by strapping
explosives to televisions.

If you use a big enough charge you get to meet Him in person. :^)

 

[Sam Goldwasser]

"Dave D" <someone@somewhere.com> writes:

A series resistor generates heat, diodes drop voltage and run cooler.. They
can be soldered into the fan leads then covered with heatshrink sleeving. A
6V supply will speed these fans up.

Not quite. If you have a voltage drop and current flow, you have IV=P
generates the same heat. Doesn't matter if it is a diode or a resistor.
The difference is that the power dissipation is roughly proportional to
current rather than a square function because the voltage drop is more or
less constant.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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Important: The email address in this message header may no longer work. To
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