Hi. I have here a JVC AV-36501U tv. Power supply puts out right about half
power. Should have 15 volts at relay coils, and I have 8 volts at that
point, as an example of voltage output. All other voltages are equally low,
and regulator waveform on primary side is correspondingly low. I wondered
about a feedback error, but can't find anything obviously bad.

I have a very similar chassis I've been using as a map, and so far have
found nothing wrong on either side of power supply, primary or secondary.

Without going into deep detail about what all I have checked, I was
wondering if any of you have run into something similar in these sets.

I have checked &/or swapped 6266 regulator, and all caps, diodes. etc in the
supply, including both optical isolators.

This one has been a head scratcher.

Thanks in advance, Danny

Make that a JVC AV-36D501U

From what I remember from a training session a few years ago, sounds
like you are on the right track. (Feedback loop open/shorted, etc.) As
part of an impressive demonstration of JVCs sturdy switching power supply,
the field trainer had us short the output of the optocoupler, where the
supply ran at reduced voltage, then he also had us unsolder a leg of the
optocoupler output, and once again the supply didn't blow up, just ran at
reduced voltage. I can tell you what most brands would've done... :-)

I guess keep digging...I no longer service this brand, and have no
schematics to help u.

wrote in message
...
Hi. I have here a JVC AV-36501U tv. Power supply puts out right about half
power. Should have 15 volts at relay coils, and I have 8 volts at that
point, as an example of voltage output. All other voltages are equally
low,
and regulator waveform on primary side is correspondingly low. I wondered
about a feedback error, but can't find anything obviously bad.

I have a very similar chassis I've been using as a map, and so far have
found nothing wrong on either side of power supply, primary or secondary.

Without going into deep detail about what all I have checked, I was
wondering if any of you have run into something similar in these sets.

I have checked &/or swapped 6266 regulator, and all caps, diodes. etc in
the
supply, including both optical isolators.

This one has been a head scratcher.

Thanks in advance, Danny