Toshiba TV29C90 problem; Image fades to black...

[Homer J Simpson]

<wrongaddress@att.net> wrote in message
news:1163478171.863838.196180@f16g2000cwb.googlegroups.com...

Well, if I leave it alone, I can only use it on hot days. I'm trying to
figure out a way I can use it on hot and COLD days?

Maybe you have a suggestion to overcome the temperature problems?

The real way to fix it is with a signal tracer and signal generator. Isolate
to a section and fault find there.

 

wrongaddress@att.net wrote:

Maybe you have a suggestion to overcome the temperature problems?

As already suggested and explained, find the fault. Anything else is
just senseless.


NT

 

[Michael A. Terrell]

wrongaddress@att.net wrote:

quietguy wrote:
How many gangs on the tuning cap? Many of the 8 transistor radios had an
RF stage - if there are 3 gangs on the tuning cap that is a giveaway

David


It's just a little pocket size radio (5 X 3 X 1.5) with 2 sections for
the tuning cap.It has the usual four RF coils and input and output
audio transformers. But that only requires 6 transistors, and there are
8 used. I suppose I can trace out the connections to try and figure out
what the extra 2 transistors do.

Does your radio have a brand name and model number?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[JW]

On Mon, 13 Nov 2006 15:32:55 GMT AZ Nomad <aznomad.2@PremoveOBthisOX.COM>
wrote in Message id:
<slrnelh41a.keo.aznomad.2@ip70-176-155-130.ph.ph.cox.net>:

On Mon, 13 Nov 2006 06:34:48 -0500, JW <none@dev.nul> wrote:


On Mon, 13 Nov 2006 04:27:41 GMT "Homer J Simpson" <nobody@nowhere.com
wrote in Message id: <1vS5h.2705$_Z2.583@edtnps89>:


lederer@ssb.rochester.edu> wrote in message
news:1163387167.767408.152950@m7g2000cwm.googlegroups.com...

I did look at this documentation. I was unaware that SATA and ATA
drives were incompatible and had different connectors. Nothing in the
Mac documentation shows a picture of what a SATA drive looks like--

Not only that but the power connectors have changed -- again!

Only on some SATA drives. I've seen SATA drives with the old 4 pin Molex
connectors.

What's the big deal? Adapters are trivially easy to get.

Yeah, but they suck. The stuff we ship is for the industrial and military
markets. Want to see how long that power connector holds on in a vibration
filled environment? As it is, we have to use locking SATA data cables when
we use the damn things. I haven't found a locking power cable yet, but,
admittedly, I haven't looked too hard.

 

[Ancient_Hacker]

wrongaddress@att.net wrote:

It's just a little pocket size radio (5 X 3 X 1.5) with 2 sections for
the tuning cap.It has the usual four RF coils and input and output
audio transformers. But that only requires 6 transistors, and there are
8 used. I suppose I can trace out the connections to try and figure out
what the extra 2 transistors do.

They often used transistors that were weak or had one dead junction as
diodes-- either as detector and agc diodes, or as biasing diodes for
the output stage.

 

[Mark D. Zacharias]

someone@somedomain.com.invalid wrote:

Sony STR-V444ES speakers audio isnt kicking in.
Good audio to the Headphones is fine.
Scoped audio up to relays is fine.
but still 27 Volts across relay coil. No signal to drop one side low
and thus kick in the relay. WHY ??? ayone run into this before?

I think I've seen bad 1 ohm resistors in the power supply cause this. In the
rear corner of the machine.

Mark Z.

 

[default]

On Tue, 14 Nov 2006 08:26:58 +1100, Franc Zabkar
<fzabkar@iinternode.on.net> wrote:

The 07D431K sounds like a 430V, 7mm diameter MOV. The fact that there
are two of them rather than just the one seems to confirm that it
cannot be a diac.

And they frequently fail shorted . . . and blow fuses

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

 

[Dave]

<haddon@gmail.com> wrote in message
news:1163306472.559937.289640@i42g2000cwa.googlegroups.com...

I recently acquired a Sun GDM-90w10 (rebadged Sony w900) 24" widescreen
crt. It is very old (manufactured Dec '97), but it was in remarkably
good condition and worked beautifully.

The extra "click" you heard was the AC main power relay being powered off.

I don't know why nobody has suggested it (I am NOT a repair professional,
feel free to correct me if I'm wrong) but if was a TV, you'd have a bunch of
posts telling you that some protection circuit had kicked in and that, given
the age of the unit, perhaps you'd be wise to check your electrolytic caps
in the power supply. Like a television, your monitor has a protection
circuit which monitors various voltages. If it detects either over or under
voltage (or DC voltage in some cases) it shuts down the unit to avoid
damage. There's a fair bit of heat generated inside these monitors, and
electrolytic caps DO dry out over time... If your SMPS voltages are all
okay, a shorted HOT would definitely give you similar symptoms.

If anybody has a schematic for you, it will save you countless hours.... but
I know Sun isn't that forthcoming with hardware manuals.

Dave

 

[tconnors23@hotmail.com]

Well I don't know much about that stove, but I do have some experience
with transducers (sensors). There's probably nothing wrong with the
transducer itself. The transducer would have to run onto the stoves
circuit board and into an a/d (analog-to-digital) converter and the
resulting hex value would have to be read by a microprocessor. The hex
value is meaningless to the processor by itself so it needs something
to reference it to to give you the resulting temperature (this is all
assuming the stove displays the temperature on a digital display). What
I'm getting at is ........bad calibration/incorrect programming on the
part of the manufacturer. Now don't take my word as gold but you might
want to look into that possibility.

 

[Bill Jeffrey]

Can you exchange the sensors, or exchange the connections, to localize
the fasult to sensor or not-sensor?

Bill
----------------

tconnors23@hotmail.com wrote:

Well I don't know much about that stove, but I do have some experience
with transducers (sensors). There's probably nothing wrong with the
transducer itself. The transducer would have to run onto the stoves
circuit board and into an a/d (analog-to-digital) converter and the
resulting hex value would have to be read by a microprocessor. The hex
value is meaningless to the processor by itself so it needs something
to reference it to to give you the resulting temperature (this is all
assuming the stove displays the temperature on a digital display). What
I'm getting at is ........bad calibration/incorrect programming on the
part of the manufacturer. Now don't take my word as gold but you might
want to look into that possibility.

 

[T Shadow]

"lj_robins" <lj_robins@comcast.net> wrote in message
news:hsSdnXqIYuyTIMTYnZ2dnUVZ_radnZ2d@comcast.com...

Hi,

I have a Maytag Gemini stove model # MER6872BAW, about two weeks ago
everyone started noticing that nothing was getting fully cooked in the
upper oven. We use the upper oven a lot so I figured it was either the
sensor or the element.

I stuck a fireplace thermometer in the upper oven just to make sure
everyone wasn't going crazy, the temp on the oven's digital display said
400 degrees, the fireplace thermometer said 310. I stuck the thermometer
in the lower oven, the display and the thermometer both said 400 degrees.

Figuring that it was the sensor I replaced it, the upper oven still
acted the same. I was able to find a schematic for the oven on
Sears.com, the sensor goes straight back to a connector on the circuit
board inside the control panel.

The new and old sensors both read a little over 1000 ohms, the sensor
connectors for both lower and upper ovens are both reading 5.15 volts
DC. My only guess on this is that there is something wrong with the
circuit board. I looked it over all the parts look fine, no burnt
resistors, none of the capacitors are bulged at the top, no popped
transistors.

The oven did give me a code F9-3 while I was working on it which decodes
to: "Check for obstruction in door lock mechanism" (there is nothing in
the mechanism). Oddly enough six months after we had this stove it gave
that code with no warning at all, it gave another code too but I do not
remember that is was. A month later it did it again, then no problems
with it at all for three years until too weeks ago.

Anyone have any suggestions on what might be wrong?

Control on our oven can be calibrated/offset. Could it have been changed?
Just brining it up because you don't mention it.

 

[James Sweet]

Dave wrote:

haddon@gmail.com> wrote in message
news:1163306472.559937.289640@i42g2000cwa.googlegroups.com...

I recently acquired a Sun GDM-90w10 (rebadged Sony w900) 24" widescreen
crt. It is very old (manufactured Dec '97), but it was in remarkably
good condition and worked beautifully.


The extra "click" you heard was the AC main power relay being powered off.

I don't know why nobody has suggested it (I am NOT a repair professional,
feel free to correct me if I'm wrong) but if was a TV, you'd have a bunch of
posts telling you that some protection circuit had kicked in and that, given
the age of the unit, perhaps you'd be wise to check your electrolytic caps
in the power supply. Like a television, your monitor has a protection
circuit which monitors various voltages. If it detects either over or under
voltage (or DC voltage in some cases) it shuts down the unit to avoid
damage. There's a fair bit of heat generated inside these monitors, and
electrolytic caps DO dry out over time... If your SMPS voltages are all
okay, a shorted HOT would definitely give you similar symptoms.

If anybody has a schematic for you, it will save you countless hours.... but
I know Sun isn't that forthcoming with hardware manuals.

Dave

Some also have a shutdown that detects lack of deflection, most monitors
have separate HV and horizontal circuits so if the horizontal deflection
transistor is shorted, cold solder joints, etc the monitor will have
similar symptoms.

 

[James Sweet]

Flyguy wrote:

Homer J Simpson wrote:

mwpmorris@gmail.com> wrote in message
news:1162839588.995972.108850@h48g2000cwc.googlegroups.com...


Could I have been exposed to anything when the glass shattered inside
the set or when I powered the thing on with the glass shattered?



No.


Do they still use mercury to flash the getter in the CRT gun assembly?
I'd be a little worried about that possbility.

Mercury is not good for you, but contacting it once in your life won't
hurt anything. I wonder sometimes about those compact fluorescent lamps
that so often end up in the trash, every one of them contains mercury.

 

[James Sweet]

meow2222@care2.com wrote:

wrongaddress@att.net wrote:


I have an old 8 gernamium transistor, protable AM radio that is noisy
on weak stations when cold. It works reasonably well when set it in the
sunshine and warms up. The problem seems to be the RF section since the
noise goes away when the volume is turned down. I'm suspecting the
germanium transistors may be the problem and wondering which one might
be replaced with a silicon variety to cure the temperature problems?

I'm not sure what all 8 transistors do. Two are in the output stage,
and another is used as a audio driver that drives the audio input
transformer.There are four RF coils, the usual oscillator (red) and
mixer (yellow) and white (1st IF) and (black (second IF). But that only
requires 6 transistors, and there are eight total. The detector is a
diode, so they didn't use a transistor for that. I haven't figured out
what the other 2 transistors do.

I'm thinking of replacing the oscillator transistor with a high gain
silicon variety to try and eliminate the temperature problems?

Any other ideas?

-Bill

Sounds like a perfect job for a can of freeze spray. Warm it up until
the problem goes away, then give suspect components a quick shot of cold.

 

[James Sweet]

lj_robins wrote:

Hi,

I have a Maytag Gemini stove model # MER6872BAW, about two weeks ago
everyone started noticing that nothing was getting fully cooked in the
upper oven. We use the upper oven a lot so I figured it was either the
sensor or the element.

I stuck a fireplace thermometer in the upper oven just to make sure
everyone wasn't going crazy, the temp on the oven's digital display said
400 degrees, the fireplace thermometer said 310. I stuck the thermometer
in the lower oven, the display and the thermometer both said 400 degrees.

Figuring that it was the sensor I replaced it, the upper oven still
acted the same. I was able to find a schematic for the oven on
Sears.com, the sensor goes straight back to a connector on the circuit
board inside the control panel.

The new and old sensors both read a little over 1000 ohms, the sensor
connectors for both lower and upper ovens are both reading 5.15 volts
DC. My only guess on this is that there is something wrong with the
circuit board. I looked it over all the parts look fine, no burnt
resistors, none of the capacitors are bulged at the top, no popped
transistors.

The oven did give me a code F9-3 while I was working on it which decodes
to: "Check for obstruction in door lock mechanism" (there is nothing in
the mechanism). Oddly enough six months after we had this stove it gave
that code with no warning at all, it gave another code too but I do not
remember that is was. A month later it did it again, then no problems
with it at all for three years until too weeks ago.

Anyone have any suggestions on what might be wrong?

I doubt that code has anything to do with the problem.

Does the control board have any analog conditioning after the
temperature probe? If so are there two identical circuits? If you can
compare readings right at the pin into the microcontroller you'd know if
the problem was before that or within it. You might simply have a bad
ADC in the microcontroller in which case you're pretty much SOL unless
you feel like writing your own code from scratch to program a replacement.

 

[James Sweet]

kyle wrote:

James,

When you say "once IT starts to burn" .. what is IT? The blue filter?
What exactly?

I have a service guy coming out wednesday.. charging me $60 trip fee,
then $175 labor + parts.. ouch! I throw the tv away at $750 all
inclusive.. who knows what else might go wrong with it

Polarizing filter. $175 sounds pretty reasonable, it's not an easy job
to tear apart the light engine, at least parts are apparently available,
for many LCD and DLP sets they weren't.

 

[AZ Nomad]

On Tue, 14 Nov 2006 05:58:21 -0500, JW <none@dev.nul> wrote:

On Mon, 13 Nov 2006 15:32:55 GMT AZ Nomad <aznomad.2@PremoveOBthisOX.COM
wrote in Message id:
slrnelh41a.keo.aznomad.2@ip70-176-155-130.ph.ph.cox.net>:

On Mon, 13 Nov 2006 06:34:48 -0500, JW <none@dev.nul> wrote:


On Mon, 13 Nov 2006 04:27:41 GMT "Homer J Simpson" <nobody@nowhere.com
wrote in Message id: <1vS5h.2705$_Z2.583@edtnps89>:


lederer@ssb.rochester.edu> wrote in message
news:1163387167.767408.152950@m7g2000cwm.googlegroups.com...

I did look at this documentation. I was unaware that SATA and ATA
drives were incompatible and had different connectors. Nothing in the
Mac documentation shows a picture of what a SATA drive looks like--

Not only that but the power connectors have changed -- again!

Only on some SATA drives. I've seen SATA drives with the old 4 pin Molex
connectors.

What's the big deal? Adapters are trivially easy to get.

Yeah, but they suck. The stuff we ship is for the industrial and military
markets. Want to see how long that power connector holds on in a vibration
filled environment? As it is, we have to use locking SATA data cables when
we use the damn things. I haven't found a locking power cable yet, but,
admittedly, I haven't looked too hard.

They don't suck any more than molex connectors in general. They're not
likely to come loose in vibration prone environments as it takes a hell of a
lot more force to separate the molex connector than it does to pull the SATA
data and power connectors out of the drive. Put a locking cable tie around
loose wire coming off the power supply and it won't come loose no matter how
many monkeys you have around your shop pulling everything apart.

 

[Franc Zabkar]

On 11 Nov 2006 20:33:42 -0800, "fireguy" <byron45@nycap.rr.com> put
finger to keyboard and composed:

My Viewsonic monitor was about 7 yrs old and I was starting to get
vertical yellow broken lines about 2" apart. Occasionally the cursor
would change to a small black vertical line. I assumed the monitor must
be bad, and bought a new one. The new one is acting the same way. Does
my video card need to be replaced, or is there an easier fix?

It sounds like a RAM failure on your graphics card. Have you checked
the fan? Otherwise, if you have integrated motherboard graphics, then
I'd check the video settings in the BIOS. The graphics subsystem on my
old SiS motherboard would misbehave in a similar way if various
timings were too aggressive. A hair dryer and freeze spray should
narrow down your fault.

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

 

[Dave]

"fireguy" <byron45@nycap.rr.com> wrote in message
news:1163306022.831703.47580@h54g2000cwb.googlegroups.com...

or is there an easier fix?

By easier you mean....what?

Really, we're talking about ONE screw and maybe $30 to replace the video
card. Well, three screws if your PC case doesn't have quick-release
fasteners.

 

[default]

On Tue, 14 Nov 2006 15:45:32 GMT, "Homer J Simpson"
<nobody@nowhere.com> wrote:

"default" <default@defaulter.net> wrote in message
news:2hljl2p78hgejco4fkq24g0tcu4gk58ng9@4ax.com...

And they frequently fail shorted . . . and blow fuses

Or shoot flames out the top!

Place I worked had some Reliance DC drives 5-100 HP range. The MOVs

would be give an audible indication that the fuses were blown - not
even the leads remained.


----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----