Digital Stream DTV converter failed

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.

capacitors

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

snip bunches......

Read all about it here....Paul

capacitors

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.

capacitors

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.

capacitors

Is it marked 12 volts? Why do you think it should be 12 volts? Capacitors don't have to be bulging to be bad.

Why did you ask here, instead of on news:sci.electronics.repair?

On Sat, 25 Aug 2012 19:40:13 -0400, "Michael A. Terrell" wrote: ...

Maybe he was looking for s.e.despair? :o)

Grant.

capacitors

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.....

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

capacitors

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.

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.

for

Looks like you have successfully debugged it ??

The engineer died! No wonder it didn't work. ;-)

for

Thanks for the laugh!!!