On one channel of my Placid BP 2.12, the D6 LED won't light and the output voltage too high 20v ish.

I've tried another LED, just touched to the bottom of the non-working LED and this won't light up either, it will on all the other LED pads. So obviously something is wrong elsewhere, but I don't know where to check first.

So I need some help as to troubleshoot what is wrong.
Tell me what and where to measure and I will measure it!

Thanks in advance.

Russ

Edited by user Wednesday, April 7, 2010 9:40:41 AM(UTC)  | Reason: Not specified

Many thanks for the suggestion Brian, I've just checked with a magnifying glass

Duff channel
QNI NPN - J5200
QP3 PNP - J1943
QN2 NPN - BC550B
Getting 20v out

Working channel
QP1 PNP - J1943
QN3 NPN - J5200
OP2 PNP - BC560B
Getting 15v out

Which I'm pretty sure is all correct?

Thanks again Brian, I really appreciate you taking the time to help me get this PS working, is there anything else I can measure or check to try and narrow things down?

Thanks again Brian, a quick check with the magnifying glasses says that all the LED's are around the right way. The others all light up.

Anything I can measure for you?

AhHa! Thank you Brian, that got me to measure the input voltage as well, one side of the transformer was very low voltage, so I replaced it with a 2x15v/15va one.

Got everything adjusted as per manual (14.95v out, R13 and R14 - at 0.06v under load) and everything seems to work fine.

Is 15va going to be enough for a Buff32s - just powering both sides of the analog?

Seems to work fine, many thanks for persevering and helping me get it to work.

Very much appreciated.

Russ