Toshiba TV29C90 problem; Image fades to black...

[Fern Dyer]

power relay sticking

"Steve" <google@stevesanyal.com> wrote in message
news:3dcd3f23.0504080633.5cafed48@posting.google.com...

Hi,

I have a Panasonic GAOO 27". I think it was made in 1995 or 1996, I
can't remember which year.

Once in a while when I'd try to shut off the power, I'd hear the
shutoff engage, but instead the screen would just go purple/magenta
rather than shutting down.

Now this happens every time I try to shut down the television. Is
this a known issue? What could be the cause?

Any help would be appreciated.

Thanks,
Steve

 

[Ray L. Volts]

"oddvark" <dgrdinh@yahoo.com> wrote in message
news:1112905062.471577.158740@l41g2000cwc.googlegroups.com...

Hello,

Have any of you had experience working on the newer 30 in Wegas? Are
they problematic? My dad wants a 30 inch wide screen, preferably flat,
but I've heard lots about problems with the wegas. Are the new ones
any better?

Thanks.

Would you like the good news or bad news first?

What the heck, here's the bad news:
I had to immediately return the first unit I brought home because the
timer/clock chip was faulty and the convergence was absolutely horrendous.
Edge and corner convergence is generally pretty crummy on WEGAs (or at least
was) considering they cost (or did when I got mine) much more than the
competitors.
The second unit I brought home had much much better convergence throughout,
so factory alignment isn't very consistent, either -- even given a generous
misconvergence allowance.
I'm comfortable making a blanket statement such as this regarding the
convergence, as I visited numerous retail stores which had these on display,
both in and out of town -- yes, I had too much time on my hands, but I also
had other things I needed to go pick up, so...
Every last one of the units in the stores, plus the two I brought home, had
varying degrees of misconvergence in the edges and corners. All were highly
noticeable and I'd go so far as to say unacceptable for Sony. Maybe they've
improved with tighter tolerances since I got mine. <shrugh>
Before people jump all over me for this, let me say that I've done my fair
share of yoke/convergence adjustments over the years and am well aware of
the difficulties in obtaining "perfect" (it's in quotes for a reason) corner
and edge convergence, particularly with larger CRT's, and especially when
rushed to do so (as factory techs would be). But that awareness doesn't
make it any less disappointing in a premium product that demands a mucher
higher price than its competitors (at that time anyway).
I compared the WEGAs side-by-side with other sets and some of the
competitors had far better convergence, but the overall pic quality was
inferior for other various reasons, which explains why I ended up buying the
WEGA anyway.
So why am I complaining then?!? Because I (unreasonably perhaps, so what)
expect more from Sony. ahh, looking through the flyers, I see WEGAs are
downright cheap nowadays compared to 5 years ago, so I'm still annoyed.
Yeah yeah, I hear you folks.. if I want zero misconvergence, buy a freakin
LCD or plasma set! That's a good idea. When can I expect you to cut me a
check?
Here's another prob an LCD unit would remedy: this WEGA's flyback started
squealing about 8 months or so after purchase. That is far too soon in my
view, and it's highly annoying. This thing is heavy heavy, so I haven't
bothered pulling it from my entertainment center to open it up and dope the
FBT and/or check solder joints, etc. It has sufficed thus far to simply tap
the cabinet or shut 'er down for a while and power 'er back up and
experience blissful FBT silence. Why not take advantage of the warranty
then? Well, it's HEAVY.. and frankly, the prob isn't severe enough to be
worthy of hauling it 40 miles out of town and damn sure not worth the cost
of shipping it. Besides, I don't want to risk getting a unit returned back
to me that's in worse shape than what I sent in, or worse a new unit with
far worse convergence.

And now, for something completely different (the good news):
My 27" WEGA is still going strong after 5 years, requiring no "actual"
repairs. While the factory alignment tolerances are annoyingly generous and
the flyback transformer prematurely sings, WEGAs are obviously designed to
produce a like-new pic way past the warranty period.

 

[NSM]

<paulodonohoe@yahoo.com> wrote in message
news:1112979375.503484.63150@g14g2000cwa.googlegroups.com...

Thanks for your help.
I am using a multimeter with capacitance function to check.
The motor does not start. In fact the unit might as well be dead except
that both the power led and "temp High" led come on.
The freezer is only 18 months old.

No warranty? Usually 5 years.

I cannot see a thermostat anywhere. Does this 25 ohm resistor serve
this purpose?

No. It's often hidden inside the back on vertical models. The dial could be
around the back also. Owner's manual?

It looks like a small wheel with contacts on either side all housed in
a small plastic unit like a plug which connects to the motor housing
via 3 pins. I'd imaging it goes open at a certain temperature so I
gather this serves as a thermostat.

Safety?

Any more ideas would be appreciated.

Kind regards

 

[Rich Grise]

On Fri, 08 Apr 2005 15:09:15 +0100, E. Rosten wrote:

On Wed, 06 Apr 2005 19:03:41 +0000, DaveC wrote:

Underlying the key mechanisms is a double-sided film with concentric
circuit pads (for each key) on either side of the film. The key cap
pushes down a little inverted cone of what looks like silicone rubber to
touch the film.

This isn't a contact switch; the top of the film has just one pad, as
does the bottom of the film; no electrical connection is being made.

Some keyborads (for instance olver versions of the Microsoft Natural
keyboards (I don't know about new ones)) have 3 sheets of plastic bonded
together. The top and bottom sheet have traces printed on, and the central
sheet has holes, but otherwise keeps the other two sheets apart. The keys
push the two outer sheets together (where there is a hole), making a
contact.
....
If you're interested, I suggest getting an old keyboard (since you can get
new ones for less than 10UKP, I expect you can get an old one for next to
nothing, and probably for free if you try hard enough) and pulling it
apart to see how it works. Many modern seem to use traces printed on
plastic with rubber domes to act as springs. Some old keyboards (like the
BBC computer) had about 70 individual switches soldered down to a board.

I've seen several that look like this:

http://neodruid.net/KeyZilla/index.html#Keyboard

Cheers!
Rich

 

[Asimov]

"Paul" bravely wrote to "All" (08 Apr 05 14:45:04)
--- on the heady topic of "Re: Multi-section cap's for Scott 299B tube amp restoration"

Pa> From: satellite65nospam@yahoo.com (Paul)
Pa> Xref: aeinews sci.electronics.repair:45278

Pa> Thanks to all who took the time to reply. Unless I find a cheaper
Pa> source for replacement multi-cans, I will probably gut the old can(s)
Pa> and stuff them with new cap's as Sam suggested. It is a fairly
Pa> shallow and crowded chassis, so adding parts underneath would be
Pa> difficult.
Pa> Any comments regarding the need to replace based on the measured ESR
Pa> values? If not, I'll probably replace only the dead ones at first,
Pa> and see if here is any hum.

Pa> On 'lytics that have not seen voltage for many years, I know that I
Pa> should bring the voltage up slowly the first time. Should I expect
Pa> the ESR to change after the first few charging cycles?


Paul, the matter of what amount is ESR is acceptable depends on the
expected working voltage and current. Older tube amps used high
voltages with low current and required less capacitance but thicker
dielectrics which typically results in greater ESR than a low voltage
high capacitance electro.

For example in a 350 volt DC supply that has 15 volts of ripple with
50mA, then 7 ohms ESR will add about a negligable 1/3 of a volt.
However, conversely if an electro is used for cathode bypass then that
same 7 ohm ESR might upset circuit conditions significantly.

Further some ESR meters may have a source of error giving a higher
reading with smaller value capacitance due to the test fequency being
too low (adds capacitive reactance to ESR) or too high (adds self
inductance from spiral plates).

On the matter of re-forming an electro, if the seal looks clean then
there is a good chance of success, and yes ESR will decrease a lot
once the electro is re-formed. Just remember a somewhat higher ESR is
to be expected with the higher voltage electros and might be normal.

A*s*i*m*o*v

.... A stereo system is the altar to the god of music.

 

[Asimov]

"borgunit2003@yahoo.com" bravely wrote to "All" (08 Apr 05 04:50:09)
--- on the heady topic of "VTVM versus new DVM"

bo> From: borgunit2003@yahoo.com
bo> Xref: aeinews sci.electronics.repair:45265

bo> Hi,
bo> I am doing a tune up on an old turntable I have and according to the
bo> service manual I need to make measurements with a VTVM (vacuum-tube
bo> voltmeter). I own a Fluke 111 DVM, is there any reason why this can
bo> not work in place of the VTVM.


JR,

The requirement to use a VTVM was given because its input is 10 Meg
ohms or more and so it wouldn't affect the circuit voltages. A DMM
typically meets a 10 Meg ohm requirement and is equivalent to a VTVM.
Rare VTVM's used a 100 Meg ohm input but the standard was 10 Meg.

A*s*i*m*o*v

.... 'Keep the smoke inside.' -- 1st Rule of Electronics.

 

[Bill Renfro]

Why do you have 3 GFCI outlets on the same circuit? Only the first one on
the line needed to be a GFCI and it would protect all the other outlets
after it. You could also use a single GFCI breaker and then all the outlets
on that branch circuit would be protected. At least that's the way mine
work.
I am glad to here you solved your problem though, I would have been
surprised as well at the reading. They really should document that.

Bill

"Nexus7" <ac25kV@yahoo.com> wrote in message
news:1112798192.360975.245590@z14g2000cwz.googlegroups.com...

I received a reply from Pass & Seymour's technical support. As part of
their "line load reversal test procedure," there is a small resistor in
the GFCI that makes it trip when the outlet is first energized. I don't
know if this procedure refers to what happens when first energized, or
if it is some other test that is performed during the manufacturing
process.

In any event, I (bench) tested this on one outlet, then on the curcuit
described. All 3 outlets duly tripped and the lights came on. After
resetting, all are open between L and N, and the circuit is functioning
correctly.

Thanks to all those who replied.

 

[Do Little Jr]

"Asimov" <Asimov@-removethis-bbs.juxtaposition.dynip.com> wrote in
message news:MSGID_1=3a167=2f133.0_4256d9cb@fidonet.org...

[.... ]

Rare VTVM's used a 100 Meg ohm input but the standard was 10 Meg.

Sorry Asimov, I find that questionable at best.
For even in 1950 - 60' any 'industrial workhorse' like the tube-type
HP 410B used 100 Meg ohms input as a standard input
It was only when the DVM came on the scene that most inputs
appeared to drop to 10 Meg Ohms.

------
I realize that physical reality is not governed by majority rule within
a small group of human beings on an "insignificant planet [orbiting]
a humdrum star lost in a galaxy tucked away in some forgotten
corner of a universe" but I was wondering what a "straw poll" here
might look like.

 

[Mark D. Zacharias]

<CptanPanic@gmail.com> wrote in message
news:1113009916.052466.255650@o13g2000cwo.googlegroups.com...

I have a sony amp that I have for about 5 years now, it has started
having a problem where the center channel will cut out, and when it
does I hear a click, like a small relay. It may have something to do
with heat also, because it seems to do it more often once the unit
heats up, though it is well ventilated. Anyone have any ideas that I
can check, and/or a schematic?
Thanks,
CP

Perhaps solder connections at the center channel relay.

Mark Z.

 

[James Sweet]

<dewdrops@2die4.com> wrote in message
news:1112765495.124632.269610@l41g2000cwc.googlegroups.com...

i hope somebody can help me. i bought a doerr pump at a garage sale the

other day. they guy tol dme it had never been used but tis a little
old. it has a strange plug almost looks like a 240 volt. but the pump
says that its 115v. i know very little about motors! when i connect it

to my outlet with some wires.. it makes a humming noise and starts to
heat up. the motor is defineitly not spinning. im pretty sure the pump
works, im just doing something wrong. any ideas? the following is on
the pump patent:3311293 insul class a 5.4 A 60HZ 1725 rpm 1/4 hp mod no

0522v103c(?)186 single phase mtr ref 50156aa733 fr h487. thanks for
your help!

Check the wiring under the cover, many motors can be wired to 120 or 240v
though I've seen a couple that only had one voltage printed on them.

 

[James Sweet]

"Ross Herbert" <rherber1SPAMEX@bigpond.net.au> wrote in message
news:323c51h8nfcfs21np29qcc0750rhp6djde@4ax.com...

On Thu, 7 Apr 2005 16:40:41 -0500, "Bob Shuman"
reshuman@removethis.lucent.com> wrote:

As I recall there were two different classes of Wega TVs. I believe one
was
a cheaper version (possibly the F or FV series?) I have had only one
problem with my 5-year old 32" model and that is with the clock. It runs
several minutes fast each month making it basically useless. Seems they
did
not take advantage of the stable 60 Hertz AC power current for clocking

Er, a lot of people actually disconnect power completely from the TV,
especially when going on holidays or for whatever reason. It is a pain
to have to reset the time every time you switch on again so that
method is also next to useless. A battery backed xtal controlled clock
would be best a-la your everday PC. Of course, the added cost would
probably mean it is unlikely to be adopted for analog sets since these
are a dying breed. Hopefully, down the track, digital TV transmissions
will all send the time locked to UTC or some other standard.

This paper covers the problem
http://www.broadcastpapers.com/sigdis/BCA03EvertzRightTime-print.htm

They use a microprocessor anyway, it's virtually trivial to allow the clock
to lock onto AC when present and use the crystal oscillator if it's
unplugged.

 

[James Sweet]

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d57482f1ddave@davenoise.co.uk...

In article <KOI4e.6601$Tm5.1917@trnddc07>,
James Sweet <jamessweet@hotmail.com> wrote:
The one area where I find an analog meter to really be easier is when
you
want to monitor the relative amplitude of some varying signal, it's a
lot
easier to visualize than jumpy digital numbers. For a quantitive value
though digital is SO much easier.

Better DVMs have a linear bar display to show you roughly the same thing.

Mine has one of those, it's really not very useful though, an analog needle
has *far* higher resolution and reacts more quickly.

 

[James Sweet]

I'd think more people would be using those LCD Oscopes that are about
the size of a big meter these days.

I've used those a couple times and really don't like them much, they cost an
arm and a leg and the performance is nowhere near that of a good analog
scope.

 

[Michael Black]

"James Sweet" (jamessweet@hotmail.com) writes:

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d57482f1ddave@davenoise.co.uk...
In article <KOI4e.6601$Tm5.1917@trnddc07>,
James Sweet <jamessweet@hotmail.com> wrote:
The one area where I find an analog meter to really be easier is when
you
want to monitor the relative amplitude of some varying signal, it's a
lot
easier to visualize than jumpy digital numbers. For a quantitive value
though digital is SO much easier.

Better DVMs have a linear bar display to show you roughly the same thing.


Mine has one of those, it's really not very useful though, an analog needle
has *far* higher resolution and reacts more quickly.


As I've said, the solution would be to put a tiny analog meter inside

the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

Michael

 

[James Sweet]

"Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
news:d37j2p$ocn$1@theodyn.ncf.ca...

"James Sweet" (jamessweet@hotmail.com) writes:
"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4d57482f1ddave@davenoise.co.uk...
In article <KOI4e.6601$Tm5.1917@trnddc07>,
James Sweet <jamessweet@hotmail.com> wrote:
The one area where I find an analog meter to really be easier is when
you
want to monitor the relative amplitude of some varying signal, it's a
lot
easier to visualize than jumpy digital numbers. For a quantitive
value
though digital is SO much easier.

Better DVMs have a linear bar display to show you roughly the same
thing.


Mine has one of those, it's really not very useful though, an analog
needle
has *far* higher resolution and reacts more quickly.


As I've said, the solution would be to put a tiny analog meter inside
the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

If they included an analog meter movment it'd probably be too small to be
useful and add too much to the cost. Easier to just keep an analog meter
around for the situations that need it. Digital is adaquate for most things.

 

[Ross Herbert]

On Sat, 09 Apr 2005 03:21:22 GMT, "James Sweet"
<jamessweet@hotmail.com> wrote:

"Ross Herbert" <rherber1SPAMEX@bigpond.net.au> wrote in message
news:323c51h8nfcfs21np29qcc0750rhp6djde@4ax.com...
On Thu, 7 Apr 2005 16:40:41 -0500, "Bob Shuman"
reshuman@removethis.lucent.com> wrote:

As I recall there were two different classes of Wega TVs. I believe one
was
a cheaper version (possibly the F or FV series?) I have had only one
problem with my 5-year old 32" model and that is with the clock. It runs
several minutes fast each month making it basically useless. Seems they
did
not take advantage of the stable 60 Hertz AC power current for clocking

Er, a lot of people actually disconnect power completely from the TV,
especially when going on holidays or for whatever reason. It is a pain
to have to reset the time every time you switch on again so that
method is also next to useless. A battery backed xtal controlled clock
would be best a-la your everday PC. Of course, the added cost would
probably mean it is unlikely to be adopted for analog sets since these
are a dying breed. Hopefully, down the track, digital TV transmissions
will all send the time locked to UTC or some other standard.

This paper covers the problem
http://www.broadcastpapers.com/sigdis/BCA03EvertzRightTime-print.htm


They use a microprocessor anyway, it's virtually trivial to allow the clock
to lock onto AC when present and use the crystal oscillator if it's
unplugged.

No matter whether the mains frequency was used as a reference or not,
and no matter whether a micro is used or not, when mains is
disconnected the only way to maintain correct time is by using a
battery backed xtal locked clock. However, it doesn't make sense to
provide both mains AND xtal locked clocks with automatic selection of
either depending upon whether mains is connected or not. Surely, if
the xtal controlled clock was included that method would always be
used to provide the time since it would have to be running all the
time no matter whether mains is connected or not. Just like in PC...

 

[Dave Plowman (News)]

In article <d37j2p$ocn$1@theodyn.ncf.ca>,
Michael Black <et472@FreeNet.Carleton.CA> wrote:

As I've said, the solution would be to put a tiny analog meter inside
the DVM, with only a relative scale on it, for this sort of thing.

Decades ago when I thought of building a DVM, I had planned to put
in such an analog meter. And I'm pretty sure one manufacturer did
include a meter like this way back.

Trouble is including an analogue meter would *vastly* increase battery
consumption.

I find the sluggishness of the LCD "analog scale" makes it completely
useless.

Agreed they're not as good.

I remember seeing one which had an LCD analogue meter complete with needle.
But I don't know if it had the same ballistics as a 'real' one.

--
*What was the best thing before sliced bread? *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Dave Plowman (News)]

In article <1112765495.124632.269610@l41g2000cwc.googlegroups.com>,
<dewdrops@2die4.com> wrote:

i hope somebody can help me. i bought a doerr pump at a garage sale the

other day. they guy tol dme it had never been used but tis a little
old. it has a strange plug almost looks like a 240 volt. but the pump
says that its 115v. i know very little about motors! when i connect it

to my outlet with some wires.. it makes a humming noise and starts to
heat up. the motor is defineitly not spinning. im pretty sure the pump
works, im just doing something wrong. any ideas?

Some vacuum pumps - like for medical use - will have induction motors
which are happy to run for very long periods. One way to start these is
via a capacitor. If that has failed - as it could with age - the motor
won't start but simply get hot.

--
*Why is the word abbreviation so long?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Mark D. Zacharias]

Butting in....

So what are you guys' favorite meters?

I mentioned my Beckman 223 died. I always liked the Fluke 77, and don't need
special stuff like frequency counter, computer connectivity or the like.

I do need it to have a tilt base and be heavy enough that simply moving
leads around won't jerk it around or knock it over.

I can pick up a good condition 77 on eBay any day for around 50.00 or so,
but that's an almost 20 year old model.

Is the Fluke 77 mark 3 any good? The 87 seems a bit big for my purposes,
though I suppose I could get used to it. What other models would you all
recommend?


Mark Z.

 

[Dave Plowman (News)]

In article <1113041834.9f8b2a4a76b747234f6c372302da2be1@teranews>,
Mark D. Zacharias <spammenot@yis.us> wrote:

Is the Fluke 77 mark 3 any good? The 87 seems a bit big for my purposes,
though I suppose I could get used to it. What other models would you all
recommend?

I've got a 179, and am very pleased with it. Does have frequency counting
though - and temperature.

Auto ranging and hold with min max.

Only think I dislike is the near rigid test leads. ;_)

--
*If work is so terrific, how come they have to pay you to do it?

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.