Toshiba TV29C90 problem; Image fades to black...

the areas you probably want to check are around the voltage regulator and
the standy circut i find that the regulator is usually close to where the
ac line goes in, before playing with a hot set i would drain everything
and flip the pcb over and go over with a magnifying glass when in doubt
resolder, then reseat all of the conectors and clean the as much dust out
of the set as you can. the only other part of the set that would throw it
into standby mode is the xray protection circut but since a gentle beating
will whip this tv into shape thats probly not the problem. but just incase
you can inspect the set for signs from electrical arcs around the flyback
and the "suction cup" on the top half of the picture tube
 
Thank for setting me straight here guys. I guess I'll have to figure out
something else.

JURB
 
maybe im not correct on this , but if you have a good picture , why are you
replacing the video head assy , arent the audio heads on the other side of
the tape path on a block rather than the big video disk?
 
The OP writes ---
Not shielding that's magnetic but rather shielding to block those
annoying rotating magnetic field radiating from the neighbor's apartment.

You can re-route the field (mu, steel etc), or cancel it with an equal and
opposite field , but you cannot block magnetism. That's my point.
bg
 
You probably have a EL display. No, there NOT leds. They take a higher
voltage to make them work. Typically 40 to 100 volts.
If there is a higher voltage at the terminals and its dead, the display is
bad. If not, the power inverter the supplies the display is bad.
Click to expand...

I've never seen an EL panel used in a car stereo, might be some that use it,
but most just use small incandescent bulbs, why I have no idea since LED's
have been quite mature and inexpensive for a while now.
 
"Harvey" <harvey@not.ntlworld.com> wrote in message
news:fLFxd.1720$032.441@newsfe1-gui.ntli.net...
[..]

Actually - describing it as a bicycle is probably a bit misleading, its more
of a scooter, with the motor permanently connected to the rear wheel by a
belt drive. There's no freewheel.
 
"mike" <spamme0@netscape.net> wrote in message
news:41C7367E.7060306@netscape.net...
Repair Traces on Glass?

A chip of glass broke out of the corner of the
display on my Palm m505 PDA. It took with it
the trace that wraps all the way around to the
other side of the touchpanel.

If I short across the break with tweezers,
the touchpanel works. But I can't figger out how
to repair the break.

The trace is silver in color; I'm guessing aluminum???

I bent a short piece of #30 solid wire into a right
angle and mashed it flat to increase the surface
area. Attached it with silver-bearing conductive
paint. The contact resistance must be too high,
cause it doesn't work.
Click to expand...

There's some conductive epoxies you could try, or that stuff you can get to
repair defroster strips on car windows might work.
 
"Harvey" <harvey@not.ntlworld.com> wrote in message
news:yaGxd.1786$032.611@newsfe1-gui.ntli.net...
"Harvey" <harvey@not.ntlworld.com> wrote in message
news:fLFxd.1720$032.441@newsfe1-gui.ntli.net...
[..]

Actually - describing it as a bicycle is probably a bit misleading, its
more
of a scooter, with the motor permanently connected to the rear wheel by a
belt drive. There's no freewheel.
Click to expand...
The relay is probably there as a safety device, preventing the motor from
being driven in case the MOSFET shorts. Check the drive circuitry for the
relay carefully, unless something is defective there then the I/O pin on the
micro is bad, I've seen it happen before on a bread machine. You may be able
to add something which will activate the relay when the MOSFET gate PWM
kicks in.
 
Once
they get the recordable/re-writable thing down solid and the price of
recorders and
Click to expand...
The thing about recordable optical is that it's much less re-recordable than
magnetic tape.

We go through about one VHS tape a year, with a programme or two recorded
almost every day (the evening news, specifically). I understand you get less
than a hundred cycles on a CD-rewritable, and I don't know about DVD-RWs.

In fact, I've noticed the "tapes only last a year" thing and became suspicious
it might be the fault of an inferior VCR (recent 'Sylvania' Funai product,
replacement for an old-but-dying Magnavox)
--
Marada Shra'drakaii
 
Thomas wrote:

Can anybody help me with this problem?

Sorry, the subject line of my message should read as above,
Click to expand...
"neutral-live electrical wiring".

Nell.
 
"Thomas" <nell_gwynne@hotmail_._com> wrote in message
news:41c7a645@news.greennet.net...
| Can anybody help me with this problem?
|
| I have someone living in my apartment while I am away. He has rung me
| up to say that in the last ten months THREE computers have "died" on him
| due to being connected to a socket in my apartment. (I think he's
| trying to make me feel guilty so that I will compensate him somehow.)
|
| He says that on each occasion his computers have been hit by a power
| surge. ...

It's not your problem. There's no way that there can be any surge that will
do that without smoking every light bulb unless it's a lightning strike
close by. He should check with his insurer to see if he is covered.

N
 
You might try contacting SONY. I had to send my DA2ES in for a repair
and they repaired it within a very few days after they received it.


On 20 Dec 2004 19:40:38 -0800, archersteven@yahoo.com wrote:

Well I researched how to test large caps and they seem to be fine. I'm
out of clues now. Maybe i'll just bring it in to a shop. The problem
is the only shop in Albany is the same shop that's had my HDTV for 8
weeks (not all their fault but still...)
Click to expand...
 
Radio Shack sells a 'pen' of conductive material. Material
is not conductive until it dries. Radio Shack P/N 640-4339.
Otherwise this stuff is hard to find.

mike wrote:
Get some circuit board repair silver Epoxy or something
similar.
What part of "silver-bearing conductive paint" did I fail to explain
adequately????
...
GC-22-0023-0000 "Silver Print II". "This Paint is air drying and leaves
a highly conductive coating"...Use to repair printed circuits...made of
pure silver..."

Can you give a specific brand/part number recommendation for something
that would work when this stuff won't??
Click to expand...
 
"Thomas" <nell_gwynne@hotmail_._com> wrote in message
news:41c7a645@news.greennet.net...
Can anybody help me with this problem?

I have someone living in my apartment while I am away. He has rung me
up to say that in the last ten months THREE computers have "died" on him
due to being connected to a socket in my apartment. (I think he's
trying to make me feel guilty so that I will compensate him somehow.)
Click to expand...

The only feasible thing that could be wrong with your wiring and cause this
(assuming north america, 120-0-120v service) is if there's a loose neutral
connection in the service panel causing an imballance between the voltages
on each side of the floating neutral. Measure the voltage at the wall
socket, if it's higher than 125v then something is wrong, otherwise the guy
is probably getting cheap junk and trying to blame you.
 
If you can get a whole PAV board for $75, I say do it! I think I paid $150
to Microdoc in Eugene aafter dinking around replacing caps and
resoldering. I can't say for sure if the PAV board is your only problem.

In article <o4Jvd.567$gt3.344@newsread3.news.pas.earthlink.net>,
Adam <kinema@gmail.com> wrote:
I was given a pile of parts that amounted to an Apple iMac DV 400
(http://www.lowendmac.com/imacs/400.shtml) awhile back. The guy that
gave it to me said that it didn't power up but that he had no idea why.
I know that iMacs of this vintage were notorious for blowing their PAV
(power, analog, video) boards. All the Mac people that I have talked to
say that the only way to fix it is to replace the PAV board because the
boards weren't fixable (such a typical Mac user solution). I don't want
to spend the $75 to buy a new board when I know that I should be able to
fix it with a few bucks worth of of the shell electronics.

After reassembly I plugged the unit in and hit the power button. All I
got was a quick blink of the power LED and a click through the speakers.
If I tried to turn it on again nothing would happen unless I had
unplugged it for a few minutes. The same thing happened when I tried
using an external monitor (this model has a standard 15 pin VGA
connection on the back) so I doubt that the flyback is the culprit.

Next I disassembled the unit to get a better look at the PAV board. I
carefully inspected it for cold solder joints and the like. I've seen
better PCB manufacturing but all in all everything looked okay. One
thing did jump out at me. The top of the large 560uF 400V capacitor
designated C905 on the PCB was domed (out not usually a good sign).
Unfortunately I don't have a ESR meter so I am unable to verify that it
is bad. Is there anyway I can test this cap without an ESR?

With my hypothesis about the capacitor I search the web for "imac" and
"C905" and found a page
(http://homepage2.nifty.com/tamaru/iMacDV/iMacDV_1.html) where the
author seems to be documenting the same problem although I can't be sure
as it's all in Japanese. On this page there are also a number of
pictures of a power IC that on my board is labeled as IC901. It would
appear that this is a Fairchild KA5S12656
(http://www.fairchildsemi.com/ds/KA/KA5S0965.pdf).

Does anyone have any experience working on these iMacs? Will replacing
the cap and/or the power transistor get this beast up and running again?
Any thoughts on where I can find the Fairchild part cheap (Digi-Key
doesn't list it and I doubt that Fry's or Radio Shack are going to stock
it). I'd love to find somewhere in the Portland, Oregon metro area that
stocks it or is able to get it easily (and inxepensivly).

--adam
Click to expand...
 
I suggest checking for bad solder connections, especially around the driver
IC's which run pretty hot on this model.

Mark Z.


"Stu-R" <stu-r@sbcglobal.net> wrote in message
news:nfbfs092a1b7v44m5cfvlvem9m08bf565j@4ax.com...
You might try contacting SONY. I had to send my DA2ES in for a repair
and they repaired it within a very few days after they received it.


On 20 Dec 2004 19:40:38 -0800, archersteven@yahoo.com wrote:

Well I researched how to test large caps and they seem to be fine. I'm
out of clues now. Maybe i'll just bring it in to a shop. The problem
is the only shop in Albany is the same shop that's had my HDTV for 8
weeks (not all their fault but still...)
Click to expand...
 
Are there boxes available than can clean
the macrovision signal for a reasonable price?
Click to expand...
Yes, and another poster here has just mentioned where.

Mike Kennedy, the other poster, suggests doing a google search for a
"macrovision remover." You may find a vendor website that sells such a device.
- Reinhart
 
Have you tried the cross reference on www.nteinc.com? It should be easy
to
find some MOSFETs with similar specs that will work.


Didn't know that site or software existed. Thanks, should make life a
bit easier in general.
Click to expand...
It does, I use it all the time. You can download and install the software
but it's easier to just use the online one.
 
"Mike Kennedy" <mikek400@R3MOVE.earthlink.net> wrote in message
news:p3Qxd.6745$yK.6476@newsread3.news.atl.earthlink.net...
| you could get a macrovision remover. they sell them on the internet just
| google it. I think i saw some for something like $30 on one site. They
also
| sell them at best buy for about +/- $65.
|
| - Mike

CAN$40 at London Drugs in Canada. Or build your own (search for Antti
Paarlahti ).

N
 
I am confused about something. Even if a power plant requires external
power to start (say, fuel pumps should be operating for some time
before water heats up and boils), it would require a lot less power
than it produces. Probably many many times less. If so, then a power
plant can buy a generator of adequate size, say 1000 kW. It should
cost a relatively minuscule amount compared to the cost of the power
plant itself.

This is completely analogous to having an electric starter on an
engine. A small, cheap piece that can get stuff moving before the main
power plant starts up in a self sustained mode.

So, just what is the problem?Have them buy adequate generators and
that's all.

Any clarification will be appreciated.

i
 
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