Solarbird 

Well swapping in the capacitor does seem to have fixed the second bad 12V PSU, it's piping out 12V happy as can be, even when transmitting.

Also it's not making the buzz noise anymore and the output's cleaner, too. (Went from like close to 100mV AC leakage to a few mV that go to zero once there's an actual load on it.)

Now just to let it run for a while, see if it keeps working.

(This isn't the one that POW!ed on me. This is the one that worked fine for a few weeks then got weird, and I found a large and apparently _very_ important cap that was very much off-spec.)

#electronics #PSU #repair #diy

Apr 4 at 10:48pmWeb
Show threadSolarbird 18h ago

six hours of operation in, no voltage drop from the power supply during transmission

i think that's going pretty well

Show threadSolarbird 17h ago

seven hours good enough i'm calling it fixed

yay

Show threadJigme Datse23h ago
@moira Off spec? wrong one used? At some point?
Show threadSolarbird 23h ago

@JigmeDatse It reads well off-label. Whether that's because it was always off-label and the power supply just put up for that for a little while, or - to my mind more likely - it was because it was shit and started dying quickly, I can't tell you.

But replacing it with one functional as labelled, the power supply seems to be ticking along like new again. So far.

We'll see if that changes once it's been running for a while, but the old one didn't need to warm up for the output to drop, so.

Show threadJigme Datse23h ago
@moira OK, that was sort of my thought more likely. That it would be very unusual for it to be wrong based on the information they were using. But that it either was failing and going off spec (don't know how likely that is to be honest, I think of them more going "pow" maybe somewhat slowly, but clearly failing than drifting...).
Show threadSolarbird 23h ago

@JigmeDatse Big Pow is kinda rare - in my experience, at least - compared to slow drift away. _Fast_ drift away is also rare, but... I think less so than Big Pow.

I've had both Big Pow and fast drift before, but... more fast drift to failure than Big Pow.

(Of course this doesn't include magic smoke release, but that's really another category entirely.)

Show threadJigme Datse23h ago
@moira OK, thank you. I haven't worked enough with this to really have much idea of what happens in the real world.