Toshiba TV29C90 problem; Image fades to black...

[William Sommerwerck]

I don't know of many cordless speakers (though I think X-10 has a system
that will work with an existing speaker). Cordless 'phones might be a better
choice.

Radio Shack. You remember their slogan: "You've got questions.
We've got C students wearing ties."

Back in April, when I went to buy a digital TV converter, the sales-boy
thought my government discount card was a credit card. I was mad, and let
the manager know. Of course, it was largely his fault. Though the kid must
have been living under a rock.

 

[William Sommerwerck]

For the step down, just make sure you get a proper transformer
and not one of these small low cost electronic thrystor types.
The electronic type of step down will damage the transformer
in your unit.

These are not transformers. They're more like a lamp dimmer.

The person rebuilding the transformer (should it come to that) might be able
to rewind for 220V.

 

[Spamm Trappe]

On Wed, 10 Sep 2008 09:03:42 -0500, cuhulin@webtv.net wrote:

I think a speaker like the kind I want is called an induction speaker?

Oh? And, what did Google tell you about that?

I know what I want, but I don't know where to buy it.

No. You don't know how to use a browser.

http://tinyurl.com/5pqecf

 

[William R. Walsh]

Hi!

The unit on the top is the old model Kill-a-watt. The one on the
bottom is the new Kill-A-Watt EZ.

Interesting. I have one of the old ones and use it so much the case
yellowed. (I can also say that the unit will read in excess of the printed
maximums--although it flashed the display and beeped unhappily about doing
so.)

Therefore, the only difference is probably software.

And the clock oscillator inside. One runs a little faster than the other.
The actual maker (printed on the PCB in mine) is Prodigit, and they have
other interesting devices that share the same case and probably a lot of the
insides.

Which one did you find to be more accurate? Inquiring minds want to know.
(And this one suggests that the unit with the higher clock rate would be it,
due to possible finer sample size...but that is just a guess.)

William

 

[William R. Walsh]

Hi!

And, what the hell is a Dream Machine? Sounds a little kinky!

It's an alarm clock sold by Sony. There's nothing special about it--most of
them are just AM/FM radios with a digital clock built in.

Oh, and some of them call the snooze button a "dream bar".

William

 

[William Sommerwerck]

"Adrian C" <email@here.invalid> wrote in message
news:6iq633FrnbauU1@mid.individual.net...

cuhulin@webtv.net wrote:

I think a speaker like the kind I want is called an induction speaker?
and there are two seperate parts.One part sits by the tv set and the
other part that contains the speaker, I can put it anywhere in my living
room I want to.I know what I want, but I don't know where to buy it.
cuhulin

I think you mean an "induction loop" system commonly used for the hard
of hearing in conjunction with hearing aids, not really with remote
speakers.

Popular Electronincs had an article on such a system more than 50 years ago!
I set it up for our TV, and built the amplified receiver. It worked very
well.

 

[Soundhaspriority]

"Tiger Luck" <Tiger_Luck@natures_preserve.afr> wrote in message
news:uy_xk.9006$np7.5413@flpi149.ffdc.sbc.com...

For the record, the amp is in an Advent 300, which I refuse to let die.

Here's a PDF of the schematics:

http://www.davidreaton.com/PDFs/Advent_300_newer_Amplifier_schematic.pdf

The cap that blows is C313. It is a 100mfd 35volt cap It is the filter cap
connecting the negative rail in the lower channel to ground. It is on the
far lower right of the schematic, just above the separate, isolated
schematic of the 15 volt regulator circuit.

The voltage on the negative rail is as it should be. The polarity of the
cap was correct. The corresponding cap in the other channel does not blow.
Both caps have the negative connected to the same source from the power
supply and both have their positives connected to ground. In other words,
the negs of both caps are connected together to the negative rail from the
power supply and both positives are grounded, yet one cap blows and the
other doesn't. The cap blew with a sharp crack and the rubber plug at the
bottom blew out. The cap that blew is not shorted. It still acts like a
cap should when measured with an analog ohm meter. I installed another,
new cap of equal value and it started heating up, so I cut the power.

I'm not a pro tech, but fairly knowledgeable and good at logic and such.

Any insights?

Take a look at the points where the + and - caps are grounded. If that part

of the ground bus is intact, but the bus is broken on the way to the supply
ground, so that it is isolated, that point could float up towards +22 volts,
making the total voltage over the cap that blows 44 volts. Which cap blows
is whichever leaks less, just a matter of chance. So check that ground bus
very carefully for integrity.

Bob Morein
(310) 237-6511

 

[don ward]

In article <r41yk.22177$89.13971@nlpi069.nbdc.sbc.com>,
Tiger Luck <Tiger_Luck@natures_preserve.afr> wrote:

Every piece of gear I have that has + and - power buss has the
positive rail cap with the + to the rail and the - lead to ground.
HOWEVER the negative rail has the - to the rail and the + to ground.
Things are not always as they seem
dnw

 

[DC]

"Tiger Luck" <Tiger_Luck@natures_preserve.afr> wrote in message
news:H32yk.37160$co7.22855@nlpi066.nbdc.sbc.com...
<snip>

Caps are no-names, both from the same parts house. hmm...
snip

Well, this may not be your problem, but things have deteriorated in the
electronic component area over the last few years. Many manufacturers have
out sourced production to China. Most if not all capacitor failures I have
seen in recent years have made in China - or no brand. Try to find something
that says made in Japan!!

Cheers

Dave

 

[Arfa Daily]

"Mikeydude" <mikeydude@hotmail.com> wrote in message
news:8K0yk.21290$mh5.1696@nlpi067.nbdc.sbc.com...

To anyone that can help,
I would like to get the values of R550 and R338.
I think I might have replaced one of them with a resistor of the wrong
value

History:
Replaced R534 and 2 shorted power transistors connected to it. (C3181N and
A1264N)
Replaced burned R538 with 100 ohm, 1/4 watt resitor.
Replaced burned unreadable R550 with 4.7k (4700) ohm resistor.
Checked neighboring resistors, transistors.

Problem now:
Stereo comes on, relay clicks on, display and controls work.
Very low volume and distorted audio is all I get.
I have to turn it most of the way up and can barely hear it.

Thanks!

Both channels ? That model hasn't by any chance got four RCA (phono) jacks
on the back marked "processor" or something similar has it ? Often have a
'bar' silk screened across them to indicate that they should be bridged.
Very low audio on what appears to be an otherwise working amp, is the
typical symptom for the bridging pins being missing. I have had many amps
that have been bought on eBay or at boot sales over the years, brought to me
for this 'fault'.

Arfa

 

[Arfa Daily]

"Tiger Luck" <Tiger_Luck@natures_preserve.afr> wrote in message
news:uy_xk.9006$np7.5413@flpi149.ffdc.sbc.com...

For the record, the amp is in an Advent 300, which I refuse to let die.

Here's a PDF of the schematics:

http://www.davidreaton.com/PDFs/Advent_300_newer_Amplifier_schematic.pdf

The cap that blows is C313. It is a 100mfd 35volt cap It is the filter cap
connecting the negative rail in the lower channel to ground. It is on the
far lower right of the schematic, just above the separate, isolated
schematic of the 15 volt regulator circuit.

The voltage on the negative rail is as it should be. The polarity of the
cap was correct. The corresponding cap in the other channel does not blow.
Both caps have the negative connected to the same source from the power
supply and both have their positives connected to ground. In other words,
the negs of both caps are connected together to the negative rail from the
power supply and both positives are grounded, yet one cap blows and the
other doesn't. The cap blew with a sharp crack and the rubber plug at the
bottom blew out. The cap that blew is not shorted. It still acts like a
cap should when measured with an analog ohm meter. I installed another,
new cap of equal value and it started heating up, so I cut the power.

I'm not a pro tech, but fairly knowledgeable and good at logic and such.

Any insights?



--
Einstein forgot to carry the two

In many years of repairing this stuff, and replacing electrolytics that have
failed any way from passively to explosively, I have only ever found three
things which cause their demise in the way you have described.

1) Excess voltage across them
2) Incorrect polarity of voltage across them
3) Excess current through them

3) is obviously the most difficult to diagnose, as it really requires a
'scope to see what's going on. However, given that this cap is effectively
in parallel with the main filter cap for the output stage negative rail, and
the one for the other channel, which is also connected to the same place for
all intents and purposes, it's hard to see how there could be excessive ac
across one of them on its own. Have you tried running the amp without the
offending cap in ? It should almost certainly run normally without it, as
small caps in that position are usually just for 'belt and braces'
decoupling purposes.

I know that you have stated several times that the cap is in correctly, but
are you *absolutely totally completely and without question* sure ? Noted
that you replaced the caps a couple of years back and have not had trouble
in the intervening period, but that is not necessarily an indication that
all was well. I have seen equipment where caps have been fitted backwards by
the manufacturers, and have lasted a long time before finally failing. If
you are basing your latest replacements which are failing, on the way you
took out the first failed one - or even based on the way that the board is
marked, because I've seen them silkscreened backwards as well - I would say
please check very very carefully, go away and have a cup of coffee, then
come back and check again. It's easy to convince yourself that you are
seeing something you actually aren't. It has happened to me many times over
the years ...

I too would like to know what you eventually find, as the circumstances you
are describing are a bit of a conundrum. If it does come down to something
you have done, please tell us. I'm sure no-one will think any the less of
you. If we're honest, we've all been there d;~}

Arfa

 

[William Sommerwerck]

I replaced all the electro caps less than two years ago. Amp
worked fine up until now. Polarity was and is correct. After
cap blew today, new replacement cap over heated. I shut off
power before it blew out.

It's remotely possible the replacement was defective. If the voltage across
the cap's location is correct in level and polarity, then that can't be the
problem.

Question... How safe is it -- other than the cap blowing -- to operate the
amp? I think you need to put a 'scope on a number of points and see what's
happening.

I don't mean to hassle you on the question of polarity, but... Japanese caps
generally have a black line on one side pointing toward the negative lead.

 

[William Sommerwerck]

Transformer has stayed cool. The 3 amp fuses on the positive and
negative rails are not blowing at this point. I don't have a 'scope, but
have a line on a Philips PM3050 for $85. There is more going on here
than I can read at the moment. I have the output pair on the left channel
yanked at this point because they shorted out. Now the output pair on
the right channel are heating up when the power is on. The electro cap
that blew is on the right channel. Part of the 15 volt regulator circuitry
failed and I replaced some parts there. But that's it for tonight.

I think you have problems that go fary beyond a bad cap. I suspect the bad
cap is a effect more than a cause.

I would start by pulling the output pair on the right channel and trying to
get everything else working correctly.

 

[Mark D. Zacharias]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:ni5yk.2451$uW7.2432@newsfe13.ams2...

"Tiger Luck" <Tiger_Luck@natures_preserve.afr> wrote in message
news:uy_xk.9006$np7.5413@flpi149.ffdc.sbc.com...
For the record, the amp is in an Advent 300, which I refuse to let die.

Here's a PDF of the schematics:

http://www.davidreaton.com/PDFs/Advent_300_newer_Amplifier_schematic.pdf

The cap that blows is C313. It is a 100mfd 35volt cap It is the filter
cap connecting the negative rail in the lower channel to ground. It is on
the far lower right of the schematic, just above the separate, isolated
schematic of the 15 volt regulator circuit.

The voltage on the negative rail is as it should be. The polarity of the
cap was correct. The corresponding cap in the other channel does not
blow. Both caps have the negative connected to the same source from the
power supply and both have their positives connected to ground. In other
words, the negs of both caps are connected together to the negative rail
from the power supply and both positives are grounded, yet one cap blows
and the other doesn't. The cap blew with a sharp crack and the rubber
plug at the bottom blew out. The cap that blew is not shorted. It still
acts like a cap should when measured with an analog ohm meter. I
installed another, new cap of equal value and it started heating up, so I
cut the power.

I'm not a pro tech, but fairly knowledgeable and good at logic and such.

Any insights?



--
Einstein forgot to carry the two

In many years of repairing this stuff, and replacing electrolytics that
have failed any way from passively to explosively, I have only ever found
three things which cause their demise in the way you have described.

1) Excess voltage across them
2) Incorrect polarity of voltage across them
3) Excess current through them

3) is obviously the most difficult to diagnose, as it really requires a
'scope to see what's going on. However, given that this cap is effectively
in parallel with the main filter cap for the output stage negative rail,
and the one for the other channel, which is also connected to the same
place for all intents and purposes, it's hard to see how there could be
excessive ac across one of them on its own. Have you tried running the amp
without the offending cap in ? It should almost certainly run normally
without it, as small caps in that position are usually just for 'belt and
braces' decoupling purposes.

I know that you have stated several times that the cap is in correctly,
but are you *absolutely totally completely and without question* sure ?
Noted that you replaced the caps a couple of years back and have not had
trouble in the intervening period, but that is not necessarily an
indication that all was well. I have seen equipment where caps have been
fitted backwards by the manufacturers, and have lasted a long time before
finally failing. If you are basing your latest replacements which are
failing, on the way you took out the first failed one - or even based on
the way that the board is marked, because I've seen them silkscreened
backwards as well - I would say please check very very carefully, go away
and have a cup of coffee, then come back and check again. It's easy to
convince yourself that you are seeing something you actually aren't. It
has happened to me many times over the years ...

I too would like to know what you eventually find, as the circumstances
you are describing are a bit of a conundrum. If it does come down to
something you have done, please tell us. I'm sure no-one will think any
the less of you. If we're honest, we've all been there d;~}

Arfa

The matching cap on the other channel may now be open, thus not exploding
from a shorted rectifier in the power supply putting AC across the cap,
which would explain the original cap failure also, and would also go a long
way toward explaining the heating on the other channel.

The multiple failure does suggest to me that you are getting AC to that
negative rail. This would explain the voltage regulator failure, and I'll
bet the main transformer is getting hot as well.

More than once I've been misled by DC voltages only to find that it was an
AC problem, either line-related or HF oscillation.

Wouldn't be surprised if the main filter on that negative rail were bad also
(or maybe it just hasn't exploded yet from the AC !).

Too bad the schematic is not complete - I would have liked to have a full
PDF on this model.


Mark Z.

 

[Mark D. Zacharias]

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:FS4yk.15584$T82.387@newsfe16.ams2...

"Mikeydude" <mikeydude@hotmail.com> wrote in message
news:8K0yk.21290$mh5.1696@nlpi067.nbdc.sbc.com...
To anyone that can help,
I would like to get the values of R550 and R338.
I think I might have replaced one of them with a resistor of the wrong
value

History:
Replaced R534 and 2 shorted power transistors connected to it. (C3181N
and A1264N)
Replaced burned R538 with 100 ohm, 1/4 watt resitor.
Replaced burned unreadable R550 with 4.7k (4700) ohm resistor.
Checked neighboring resistors, transistors.

Problem now:
Stereo comes on, relay clicks on, display and controls work.
Very low volume and distorted audio is all I get.
I have to turn it most of the way up and can barely hear it.

Thanks!



Both channels ? That model hasn't by any chance got four RCA (phono) jacks
on the back marked "processor" or something similar has it ? Often have a
'bar' silk screened across them to indicate that they should be bridged.
Very low audio on what appears to be an otherwise working amp, is the
typical symptom for the bridging pins being missing. I have had many amps
that have been bought on eBay or at boot sales over the years, brought to
me for this 'fault'.

Arfa

Or the Tape Monitor (or "Tape 2") switch engaged...

Mark Z.

 

[Dave Plowman (News)]

In article <d20dc45v099rscl6l107ddqrq57lag9umf@4ax.com>,
Ardent <iam@here.com.invalid> wrote:

Someone plugged my Dream machine (rated 110 VAC) into a 220 VAC outlet
and the transformer primary got trashed. Since I will be living here
for a while I thought of getting a transformer made here locally (very
cheap, honest).

I'm willing to bet it's rather more than just the transformer. Copper
takes time to melt while solid state destructs near instantly.

--
*Why isn't 11 pronounced onety one? *

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

 

[Wayne Tiffany]

Does anyone have a case sitting around that would fit this model? I was
given one that the front shell and board supts are busted up. The back is
fine, though. I have a KV27S15, but the cases are too different to make it
work. The TV appears to work as long as you hold everything so it doesn't
touch.

I am in the Kansas City, MO area. Thanks.

WT

 

[Wayne Tiffany]

Does anyone have a case sitting around that would fit this model? I was
given one that the front shell and board supts are busted up. The back is
fine, though. I have a KV27S15, but the cases are too different to make it
work. The TV appears to work as long as you hold everything so it doesn't
touch.

I am in the Kansas City, MO area. Thanks.

WT

 

[Wayne Tiffany]

Does anyone have a case sitting around that would fit this model? I was
given one that the front shell and board supts are busted up. The back is
fine, though. I have a KV27S15, but the cases are too different to make it
work. The TV appears to work as long as you hold everything so it doesn't
touch.

I am in the Kansas City, MO area. Thanks.

WT

 

[Wayne Tiffany]

Does anyone have a case sitting around that would fit this model? I was
given one that the front shell and board supts are busted up. The back is
fine, though. I have a KV27S15, but the cases are too different to make it
work. The TV appears to work as long as you hold everything so it doesn't
touch.

I am in the Kansas City, MO area. Thanks.

WT