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Digital Stream DTV converter failed

I bought it several years ago, but it was just in the closet as a spare.
I've only used this DTV converter for a couple months. Today it
suddenly just shut off and left snow on the tv screen. If I unplug it,
the front LED lights for a second and shuts off. I'm suspecting a
capacitor.... Anyone know of a common problem with these converters?

Thanks
 
I don't know how common, but I had one fail after a thunderstorm. Sure
enough, there were bulging capacitors. That was DS model DTX 9950,
or DTX-9900 (I have one of each, and don't recall which). Replacing the capacitors
fixed it.

We had a thunderstorm last night, but it did not fail till hours later.
However it's possible the storm did some damage. This converter is in
my workshop so I dont know which model I haveright now, but they only
made 2 or 3 models. I believe mine has analog passthru. I'll have to
open it and look at the caps. Seems this is the #1 problem on all
electronics these days. Too bad they make such crappy caps these days.
Hell, I have old radios and stuff from the 60s and 70's that still work
fine and no caps have been replaced. I think this is preplanned
failure. If they could make good and long lasting caps 50 years ago,
why cant they make them as good or better now?
 
P

Phil Allison

Jan 1, 1970
0
We had a thunderstorm last night, but it did not fail till hours later.
However it's possible the storm did some damage. This converter is in
my workshop so I dont know which model I haveright now, but they only
made 2 or 3 models. I believe mine has analog passthru. I'll have to
open it and look at the caps. Seems this is the #1 problem on all
electronics these days. Too bad they make such crappy caps these days.
Hell, I have old radios and stuff from the 60s and 70's that still work
fine and no caps have been replaced. I think this is preplanned
failure. If they could make good and long lasting caps 50 years ago,
why cant they make them as good or better now?

** They can and they do - but you need to pay a bit more for them. Name
brand electros rarely give any trouble in sensibly designed circuits and can
last more than 20 years.

The electros that show short lives are usually of the "no brand " kind, are
extraordinarily small for their ratings and are forced to run hot in the
particular device. All the above are ways to economise.

Another big factor is where the electros are used in a device ( like a
television STB, wall wart SMPS or PC power supply ) that is operating
almost 24/7. This means they clock up over 8000 hours a year and that is a
LOT of use.

Fitting name brand ( ie Nippon Chemi-Con or Panasonic ) electros to my STB
and switching it OFF at the AC supply -electro cap life has been multiplied
by 5 times or more.


..... Phil
 
We had a thunderstorm last night, but it did not fail till hours later.
However it's possible the storm did some damage. This converter is in
my workshop so I dont know which model I haveright now, but they only
made 2 or 3 models. I believe mine has analog passthru. I'll have to
open it and look at the caps. Seems this is the #1 problem on all
electronics these days. Too bad they make such crappy caps these days.
Hell, I have old radios and stuff from the 60s and 70's that still work
fine and no caps have been replaced. I think this is preplanned
failure. If they could make good and long lasting caps 50 years ago,
why cant they make them as good or better now?
That's an unfair comparison. In the '60s and '70s, switching power supplies
were rare, they were ten times larger, and didn't work 24x7. Perhaps you'd
like to go backwards, but I much prefer the consumer electronics we have
today.
 
I don't know how common, but I had one fail after a thunderstorm. Sure
enough, there were bulging capacitors. That was DS model DTX 9950,
or DTX-9900 (I have one of each, and don't recall which). Replacing the capacitors
fixed it.

I opened it and there are no bulging caps or noticable burnt parts. I
checked the voltages on the plug from power supply board to main board.
From ground (black wire) to red, I get 5 volts. From black to orange I
get 3 volts. Shouldn't that be 12 volts rather than 3v?

When I plug in that plug to the main board, or plug in the entire unit
to a wall outlet, the green LED only lights for a second or less.

Thanks for all help.
 
Is it marked 12 volts? Why do you think it should be 12 volts?
Capacitors don't have to be bulging to be bad.
It's not marked, but all computers have 12 and 5 volt from their power
supply, and those converters are similer.

I wish they put schematics for those DTV boxes on the web.....
Why did you ask here, instead of on news:sci.electronics.repair?

Because AIOE has that group blocked. I tried it already. It;s been
blocked for at least a year or more.
 
W

whit3rd

Jan 1, 1970
0
Since when is a cheap set top box a computer? 3.3 volts & lower is
quite common for digital ICs these days, and the 12 V from a PC power
supply is the source for onboard regulators.

It's likely a digital converter will need lots of 3.3V for logic, some +30V for
tuner functions, and maybe +/- voltages for serial port/remote/smart antenna.
The O.P. has a 120VAC input box, and there's lots of internal power, probably
little if any is 12V or 5V.
 
It's likely a digital converter will need lots of 3.3V for logic, some +30V for
tuner functions, and maybe +/- voltages for serial port/remote/smart antenna.
The O.P. has a 120VAC input box, and there's lots of internal power, probably
little if any is 12V or 5V.

After using a magnifying glass, I noticed it says 5v and 3.3v on the
board, plus grounds, by that plug. So, the voltages are correct. And
here's a real weird one. There is a metal cover over the input ANT and
output TV connectors. I popped that cover off, and the converter began
working, and has been working ever since. I put it all back together
and it's working fine. However, I found a dried up bug inside of it.
Could that bug have shorted something until it dried??????
Guess I'll never know.....
It's woking perfectly again, and has been on for 2 days.
 
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