Peter Chou USP-11-150 PSU

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I purchased a cabinet with this power supply in it. It was non-functional when I got it, but it had a nice cutout in the cab already, and a nifty power button, so I decided to try to fix it.

Recapped it (all but the two big caps), replaced the power inlet, replaced the fan, and removed all the rust inside and out.

When I reassembled it it worked! Untill... any time I attempt to adjust the 5v DC at the pot, a faint buzz begins and all DC voltage is lost. AC is still passed through though.

I can adjust the pot while the power is off and when I turn it on the voltage is what I would expect at that position, but any adjustment while power is on shuts it down.

Is this an issue with the pot? One of the ICs? The two big unchanged caps?

Oh, also, when I get my 5v to what I'm shooting for (5.10v) the 12v is only at 9.99v. Not sure if that's related.
 
Maybe start with Deoxit'ing the pot, and if that doesn't help, replace it
 
I purchased a cabinet with this power supply in it. It was non-functional when I got it, but it had a nice cutout in the cab already, and a nifty power button, so I decided to try to fix it.

Recapped it (all but the two big caps), replaced the power inlet, replaced the fan, and removed all the rust inside and out.

When I reassembled it it worked! Untill... any time I attempt to adjust the 5v DC at the pot, a faint buzz begins and all DC voltage is lost. AC is still passed through though.

I can adjust the pot while the power is off and when I turn it on the voltage is what I would expect at that position, but any adjustment while power is on shuts it down.

Is this an issue with the pot? One of the ICs? The two big unchanged caps?

Oh, also, when I get my 5v to what I'm shooting for (5.10v) the 12v is only at 9.99v. Not sure if that's related.

as noted, the adjustment pot is dirty. when it can't get a read on what it's adjusted to it shuts down, as it's supposed to.

+12V will be low if you're running a switching power supply without a load.
 
Thanks, I'll give those suggestions a shot.
 
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