Toshiba TV29C90 problem; Image fades to black...

[Clarence]

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com> wrote in
message news:10nnfl5q5hfurcf@corp.supernews.com...

William P.N. Smith> wrote in message
news:4p3ln058j0n4ept11i778t4hig192mg6ur@4ax.com...
"keepcold" <keepcold@comcast.net> wrote:
I have a about 100 different bags of sony factory sealed circuits
used for
repair of tv's dvd players...ect
Most of these bags have like 4 or 5 of the same part..
There are too many part #s to post but if anyone is intrested i will
post
them.... Make me an offer

I'll give you a dollar for all of them.

Pig in a poke, eh? "If you can guess how many chickens I've got in
this bag, I'll give you all five of them."

Why din'tcha say "I'll give you 100 cents for them" and give the guy a
conniption fit when he thought you meant dollars... Or offer him forty
thousand quatloos.

I've got a bunch of 100k full-size pots with a SPST pn/off switch on the
back that I'll trade for them. I have a couple bags, must be over a
hundred. Problem is they're lin, not log taper. What kind of circuit
uses a lin pot with an on/off switch? Tone control? Squelch? What
else?

Power supply!

 

[Mike Kennedy]

You say the thing doesnt dial either.. why waste time fixing a $25 phone!?
http://www.hypaudio.com/kxtc1484b.html

I have the older model of this phone and it has problems with the microphone
gain and static on the phone.
Get A NEW PHONE.


"G.S.V VIKRAM" <gsrivikram@yahoo.com> wrote in message
news:ba6c0e3c.0410230125.7daaca94@posting.google.com...

I've your New Model PANASONIC CallerID phone by the Model No
KX-TC1484B having the facility pulse-or-tone dailing capability.
But, right from using this phone we are unable to recognise the phone
number of the caller. I mean Caller Number is not displayed. Rest of
the things are asusual and working properly.

So could you please guide us how to get it? Even I have
tested my phone line with other phone set having CallerID facility.
They are displaying accuratly.

We are eagerly waiting for your Mail.

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/04

 

[t.hoehler]

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.

Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom

 

[Watson A.Name - \"Watt Su]

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOSPAM@dslextreme.com>
wrote in message news:10nnofj3q4lhe5b@corp.supernews.com...

"Clarence" <no@No.com> wrote in message
news:8XPed.18184$nj.7295@newssvr13.news.prodigy.com...

"Watson A.Name - "Watt Sun, the Dark Remover""
NOSPAM@dslextreme.com
wrote in
message news:10nnfl5q5hfurcf@corp.supernews.com...

William P.N. Smith> wrote in message
news:4p3ln058j0n4ept11i778t4hig192mg6ur@4ax.com...
"keepcold" <keepcold@comcast.net> wrote:
I have a about 100 different bags of sony factory sealed
circuits
used for
repair of tv's dvd players...ect
Most of these bags have like 4 or 5 of the same part..
There are too many part #s to post but if anyone is intrested i
will
post
them.... Make me an offer

I'll give you a dollar for all of them.

Pig in a poke, eh? "If you can guess how many chickens I've got
in
this bag, I'll give you all five of them."

Why din'tcha say "I'll give you 100 cents for them" and give the
guy
a
conniption fit when he thought you meant dollars... Or offer him
forty
thousand quatloos.

I've got a bunch of 100k full-size pots with a SPST pn/off switch
on
the
back that I'll trade for them. I have a couple bags, must be over
a
hundred. Problem is they're lin, not log taper. What kind of
circuit
uses a lin pot with an on/off switch? Tone control? Squelch?
What
else?

Power supply!

I've been noticing that all the HP PSes, even the cheap ones, use
wirewound pots for the V and I controls. They even specify the PPM
tempco. Some use the three turn precision pots, better ones use the
ten-turn pots. I think it makes a great deal of diff in the stability
and repeatability of the settings.

The pots I have are all carbon, and the value is a bit high for most
linear PSes, such as a LM317, where 5 or 10k is about as high as
you'll
ever need.

I dood a google search for 100k pot schematic, and the first hit I got
was an old favorite that I'd almost completely forgotten about.
Heh-heh. But times have changed...
http://www.phrack.org/show.php?p=33&a=9

But in this same search I found a simple way to change the 100k lin pot
to log.
http://sound.westhost.com/pots.htm - skip down to 'Changing The Law Of A
Pot'

 

[Graham]

Hi:
One minute my RCA RP2450C is working fine. The next, when you turn it
on the message "Upgrade, Start Run" appears in the display, no matter
what you do it next displays "reading file..." It will not turn off
unless you remove the battery. If you start it up withou a disk in it,
it still gives the first message and then displays "No Disk, upgrade
prog". Help! Nothing has been spilled on it. Lens is clean. Disk is
turning.

Regards

Sound like its waiting for you to insert a software update disk.

Maybe the flash memory is corrupted and that's what it does in that
circumstance.

You might like to watch this thread,
http://snipurl.com/a12j
looks like someone with the same problem. You might have to brush up on your
Polish though!


Graham.

%Profound_observation%

 

[John Del]

Subject: Re: Fs/Factory sealed sony circuits
From: "Watson A.Name - \"Watt Sun, the Dark Remover\""

Or offer him forty

thousand quatloos.

Quatloos ain't worth diddly since Kirk handed that drill throll his ass.....

John

 

[Franc Zabkar]

On 23 Oct 2004 23:40:46 -0700, easytoremember123@email.com (Wizard of
Ozz) put finger to keyboard and composed:

I just bought a Samsung Syncmaster 793s 17" monitor. I'm using a very
old computer, with a very old video card, a SiS 6326 (Silicon
Integrated Systems) from 1997. I'm using Windows 98.

<snip>

After reading the monitor CD manual to make sure I wasn't doint
something I would regret, I manually changed the refresh rate to 85 Hz
(always at 800*600). Perfect! Beautiful image. Except...

There are these evenly spaced vertical lines, just noticeable, across
the screen. Others might not complain about them. I'm a perfectionist
(there's a bit about perfectionists in the FAQ). There's 7 of them.
They weren't there at 75 Hz. Very evenly spaced, about 4.2 cm apart
(1.65 inches). They are each 1 mm thick (0.04 inches). They seem to be
slightly brighter than the sorrounding picture. On a black image they
don't appear, but on a uniform image of white, red, blue, or green,
they do. When viewing text, I can't notice them, though they still
appear in the blank parts of the text screen. They stretch from top to
bottom. The 2 closest to the left and right side of the screen are
about 2 and 3 cm respectively from the edge of the screen.

If I move the screen using the controls on the side of the monitor,
the lines move with the screen.

Do the lines move with the raster, or do they move with the video
content? What happens if you display a black screen and max out the
brightness and contrast?


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Art]

Gov: you may want to post the model number and chassis number if available.
Basically my guess would be some type of power supply or protect problem.
Generally one will need to open the tele up and do some basic diagnostics
inclusive of verifying presence of necessary standby and operating
potentials. Also making sure that nothing got disconnected or cracked as a
result of transporting it.
"Toby Marsden" <toby@toby.org.uk> wrote in message
news:cfd28c0e.0410241159.264e2a3d@posting.google.com...

Hi folks,

I've just bought a second hand Mitsubishi TV - worked fine in the
vendor's house, but got it home and although it will go onto standby,
any attempt to switch it "on" and get a picture displayed results in
it turning itself off within 1/2 second or so, and remaining
completely off for anything up to a minute, until the whole thing
starts again.

Does this point to anything in particular? I'm thinking it must have
got bashed in the car on the way back, but I really don't remember
this happening...

TIA for any help,

Toby
--
Toby Marsden
Berkshire, UK

 

[Chuck Harris]

"doublespaced" drives are drives that use a software compression
scheme to increase (on average) the amount of data that can be stored.

-Chuck

Dbowey wrote:

Lenny posted:

(BIG snip)

I'm not familiar with the term "doublespaced" drives. Is that like a two-HD
RAID set to mirror so that each drive stores identical info?

I recently did battle with a Windows system that used mirroring. One HD was
corrupting data. I broke the RAID, disconnected the bad one and booted from a
CD to read the data from the good drive (it wasn't bootable).

If that is what's going on with yours, you should be able to do essentially the
same in DOS. You can probably pick up a usable, 40Meg drive for nearly $free,
and do a disc copy to mirror the good drive.

Good luck

Don

 

[Kim Clay]

On Sun, 24 Oct 2004 10:45:19 -0700, "Watson A.Name - \"Watt Sun, the
Dark Remover\"" <NOSPAM@dslextreme.com> wrote:

<snip>

But in this same search I found a simple way to change the 100k lin pot
to log.
http://sound.westhost.com/pots.htm - skip down to 'Changing The Law Of A
Pot'

You may also find "The Secret Life of Pots" good reading
http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

About 1/2 way down it gets into tapering & added "tapering resistors".

Kim Clay

 

[Jim]

2 jobs ago I used to have to repair HD's & sometimes I'd see something like
this.
I would say it's most likely an overheating IC. All you'd need is Freeze
spray (or a can of compressed air upside down) to find the specific chip.
Or if you were like me, just pull a duplicate PCB out of the bin from a
drive that did fail mechanically & try swapping it. Bios chip must be the
same though

(Yes we replaced Lots of dead drives.)

Typically if it's the mechanicalls failing, you get High Pitched noise, or
the Aluminum Case would get Real Hot from the bearings failing.


jim

"Ken" <user@domain.invalid> wrote in message
news:Fqhed.748819$Gx4.273692@bgtnsc04-news.ops.worldnet.att.net...

I recently struggled with recovering data from a HD that would not run
CHKDSK from another Win XP boot drive. After having tried many things,
I placed the drive into the freezer for a couple of hours and found that
I could copy some of the data I wished to recover and store it on the
master HD while it was attached as a slave drive. Once the drive warmed
up, I encountered more difficulty in readying additional data.

Encouraged by the data I had been able to recover, I placed the HD back
in the freezer. When I took it out, and this time while insulated by a
plastic bag so that it did not short the electronics, I packed it in ice
and attached it as a slave drive again. This kept the drive cold
longer, and I was able to recover even more data and for a longer period
than the first effort.

To make a long story short, I was able to retrieve 700 MB of data and I
deemed the effort a success. My question is: Why was data able to be
read when the HD was cold and not once it warmed up? Some articles I
have read seemed to attribute this to mechanical reasons related to the
application of cold. I was wondering if it was not more related to the
effect that the cold temperature might have on the semiconductors. That
is it might reduce the internal resistance enough to cause a signal to
be detected where one would not be detected if warm.

Any comments???

 

[Sparkchaser]

I know that Mr. Lee did not supply any technical information but he did
supply enough for someone that has seen these symptoms to recognize them
immediately. I too have a June 2002 unit and it has the exact same
problem. I also have some experience in troubleshooting televisions but
why would I want to troubleshoot this particular problem when it seems
that this is a common fail and hopefully someone has came up with a fix
for it already. I cannot speak for Mr. Lee but I know for certain that is
exactly what I am hoping for. If someone does know of a fix for this
problem I would greatly appreciate any and all information that is
provided.

 

[Tim Wescott]

larrymoencurly wrote:

If an electrolytic capacitor tests out OK with an ESR meter, is it
normal for it to go bad (high ESR, bulging) just two weeks later, even
if it's one of those Taiwan brands that was made with defective
electrolyte?

I noticed that my computer's 2-3 year old 300W Antec power supply had
a leaking electrolytic, so I replaced it and checked ESRs of all the
other caps. They all measured less than 0.05 ohm (out of circuit --
too many in parallel), with no leaks or bulges, the bad one about 0.6
ohm. Two weeks later, I just happen to have the power supply apart
(no problems with it) and see that one of the capacitors that tested
OK is now bulging, and its ESR is 0.15 ohm. This computer isn't a
power hog but draws only 50W or so (1A @ +12V, the rest from +5V), and
I don't think the power useage or temperature have changed recently.

I don't know, but it sure bears out the general rule that if you have a
group of components with one bad, you should replace the whole batch
whether they be brake shoes or capacitors. After all, the time to do it
is when everything is ripped apart anyway.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Tom MacIntyre]

On Sun, 17 Oct 2004 11:12:58 -0400, "john"
<va3mmTAKEOUTTHIS@niagara.com> wrote:

Dont forget to tell the poor tech that
you screwed it up in the service menu,s.
when you take it in to get repaired.

kip

Right...I once ended up having to charge a guy about 40% more than it
should have been, when, after a time of troubleshooting in circles, I
finally figured out that he was into the (analog) controls
first...totally unrelated to the original problem also.

Tom

 

[mark]

Mabe you put it back backwards.

"Tim Wescott" <tim@wescottnospamdesign.com> wrote in message
news:10norp2nko05v53@corp.supernews.com...

larrymoencurly wrote:

If an electrolytic capacitor tests out OK with an ESR meter, is it
normal for it to go bad (high ESR, bulging) just two weeks later, even
if it's one of those Taiwan brands that was made with defective
electrolyte?

I noticed that my computer's 2-3 year old 300W Antec power supply had
a leaking electrolytic, so I replaced it and checked ESRs of all the
other caps. They all measured less than 0.05 ohm (out of circuit --
too many in parallel), with no leaks or bulges, the bad one about 0.6
ohm. Two weeks later, I just happen to have the power supply apart
(no problems with it) and see that one of the capacitors that tested
OK is now bulging, and its ESR is 0.15 ohm. This computer isn't a
power hog but draws only 50W or so (1A @ +12V, the rest from +5V), and
I don't think the power useage or temperature have changed recently.

I don't know, but it sure bears out the general rule that if you have a
group of components with one bad, you should replace the whole batch
whether they be brake shoes or capacitors. After all, the time to do it
is when everything is ripped apart anyway.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Richard Clark]

On Wed, 20 Oct 2004 12:31:41 -0500, "jakdedert"
<jdedert@bellsouth.net> wrote:

With a system set up as described, I'm surprised he doesn't get some
ghosting on channel 13 from the reflected signal coming off his main
antenna. If so, trapping that channel before the splitter (combiner) would
reduce the effect.

Hi jak,

Reflected signals on a nearby antenna (like one on the same mast) is
going to be totally invisible. The scan line crosses the screen in
62ľS and an RF signal will travel 10 Miles in that time. For a ghost
to be observed the original and the reflection must exhibit some
significant portion (or multiple plus offset) of that value. Let's
arbitrarily call your TV 10 inches wide and set the reflection with a
1 mile path difference. Thus the two images (original and ghost)
would be offset by one inch.

Now let's ramp that 1 mile difference down to a couple of feet (those
two adjacent antennas). You should then appreciate that 1 inch ghost
offset will shrink to sub mm (to mix units). Conventional TV
bandwidths could not resolve the difference.

73's
Richard Clark, KB7QHC

 

[Jim Adney]

On 18 Oct 2004 09:23:14 -0700 captainvideo462002@yahoo.com (Lenny)
wrote:

I'm running a 386/25 with Dos 6.2 for billing. The unit has two
Seagate MFM 40Meg drives that are doublespaced. It uses Qemm as a
manager, and the high memory area is being used. I use "Optimize" to
configure the memory. Scandisk found a problem on the E drive that it
can't fix and I hesitate to use Norton as this could make things
worse. Recently it has been having problems with bad sectors on the
drive showing, and refusing to boot unless you boot off a floppy and
do a sys c: from the A drive. Of course if you boot off the floppy and
then try to access programs they will either not run properly or there
isn't enough memory to operate them possibly due to doublespace not
loading? Anyway, now it will only boot if I'm lucky.

I see two possible solutions. Both require that you get a second hard
drive and install it on this computer as a secondary drive. Since your
40MB hard drive is an MFM, you will probably want to get a drive card
which will support IDE hard drives. Attach a 100MB or more IDE drive
to that card. You said you were having trouble with the E: partition,
so I gather that there are multiple partitions on your MFM drive.

1) Install the second hard drive, including getting it configured in
the BIOS. Boot to a floppy and fdisk partitions on that drive, as many
as you have on the first drive, with each partition at least twice the
size of the corresponding partion on the first drive. Format all the
partitions on the second drive and then sys the first one and set it
active.

Then try to boot to your original disk. Keep trying until it works.
Once you're in, use xcopy (you'll have to check the options) to copy
each entire partition to its corresponding partition on the second
disk.

2) If you can find anyone with Partition Magic (any version), borrow
the floppies and boot to them. Use Partition Magic to copy the each
partion on the first disk to the second disk. This may take several
tries, because PM will complain if it finds problems with the
partitions.

Once the partitions are copied, use PM to set the first partition on
the second disk active and then shut down and remove the first disk.

both methods:

Record and then remove the references in the BIOS to the first disk.
After this you should be able to either boot to the second disk, or
move this disk to a newer machine and boot to it there.

This should work, but only if you can get this drive to work
temporarily. If you're not familiar with this stuff, however, it will
seem overwhelming and you might want to get some help.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

 

[Mike]

In article <clb9jp$81g$1@beta.qmul.ac.uk>, davew <davew@elec.qmul.ac.uk> wrote:

Also we supply goggles and these are very cheap when you consider
they could save you're eye from molton flux or even solder.

As a specs wearer, I can vouch for that. About 3 times, I've been splatted
right in the centre of a lens ... and not while doing something
particularly dangerous!

If you're planning on reclaiming components get a solder sucker and some
desolder braid.

Or an electric hot-air gun. Great for mass desoldering of components where
you don't want the board back.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[at]pootle.demon.co.uk | http://www.pootle.demon.co.uk/

 

[Techforce]

2436493A supercedes that part no.

Originals In stock here:
http://search.yahoo.com/search?fr=slv1-iy&p=2436493a



"I. Frank" <ilanfrank@yahoo.com> wrote in message
news:d564a715.0410250855.4db5cce1@posting.google.com...
|I have a Hitachi 50EX12B (50" Projection TV purchased in 1996) that
| stopped working a few weeks ago. My investigation leads me to believe
| that there is a short in the flyback transformer (part# 2436493).
| However, I called every Hitachi authorized distributor in America and
| they are all out of stock and the part was discontinued last year.
| Does anyone know where I could get one of these?

 

[Norm Dresner]

My OP contained an error in that the voltage on the +20 regulated supply
line wasn't zero but in fact was 27V. Or maybe it was zero the first time I
powered up the unit measured it and then something "snapped" and it went to
27V. [Maybe I measured the wrong thing the first time -- we'll never know.]
In any event, the last 3 times I've powered the unit the voltage is a
clearly unregulated ~27V which results from the output of U420 (the error
amp) being stuck as high as a 741 will go in spite of the imbalance in the
inputs with the voltage at the inverting input almost 2 volts higher than
the voltage at the non-inverting input. The voltages at the pass transistor
Q420 are completely consistent with it being perfectly sound and just being
driven into (near) saturation. There are no shorts in this transistor.
Neither is there any problem with the current-limiting transistor either.
All voltages in the +20V regulation circuit are consistent with a failed Op
Amp and with no other hypothesis I can propose.

As far as I can determine, all of the other voltage regulating circuits are
functioning "properly" -- that is their outputs are all perfectly
proportional to the 27V on the 20V line as they're supposed to be.

Based on the serial number this is an early unit. The Op Amp at U420 has
completely different markings from the other 741's in the unit which are all
of a single type. The soldering on U420 looks exactly like the others and
there are absolutely no signs of any hand-work in replacing it; I have to
believe that it's the original as it came from the factory.

The voltage on the +5V line is ~6.7 volts. There is a single TTL IC (7402)
and an MC1711CL which IIRC is some kind of ECL gate. Neither of these would
be very happy with almost 7V on Vcc. Everything else on the board is either
discrete transistors or 741's (or similar) so I don't think that any of the
other ICs would have been damaged. While the sine shaper might not put out
a good waveform with the higher voltage, none of the other outputs are
working either so I suspect there's a fundamental problem with the main
oscillator. That's why I'd like to simply substitute a a good +20V supply
for the output of this circuit and see if the rest of the unit is intact.
It may in fact not be and it may simply not be worth the time to debug it.
I've been thinking that I could easily rig up an LM317 (as you suggest) or
an LM7818 to substitue for this circuit.

My point in checking for oscillations was that sometimes an oscillating Op
Amp can give some very strange readings on a simply DMM.

Norm