P5 fuse blows

That’s bizarre and seems like you have the opposite problem, except my P5 is bricked now. I also have a P10 and it’s working fine. What are your settings for multi-wave and output voltage? Try using a sine wave with 115 volts out.

OK, it’s not the transformer. I disconnected one of the output rails and it powered up with no load. Not functional, but I have isolated the fault to one side of the regenerator, and at least it’s no longer bricked. I still think I will send it in because I don’t want to buy expensive parts and end up frying something again.

I’m trying to get support to send me a guide as to how to test the transformer’s outputs. I asked last week but have not received anything. Obviously it could work differently when under load (e.g. if there are loose laminations) but a basic test of the unloaded output voltages must be possible and I can’t believe that PS can’t provide the information. I’ll email support again later today. I’d have thought they could send me the information by return. I’ll let you know the outcome.

In my experience, the odds of you having a defective power transformer is very low to begin with.
If I understand correctly, you have unloaded all the secondary outputs of the transformer and the fuse does not blow.
That almost eliminates the power transformer as the culprit.

I guess anything is possible, but I would look elsewhere first.

In my case the fuse blows immediately with nothing connected (the ethernet was connected but that’s all). Dan.

Dan, what I did to unload the secondary was to unplug the regen board internally. On the P5 that’s just 3 heavy wires on the left side (blue, brown, black) connected to the regen board with spades, so easy to remove and reconnect. I was lucky and did not have to touch the right side. The unit is not able to properly regulate the voltage in this configuration but it was happy enough to power up.

Not sure if the P10 is similar, but I believe this is the most logical first step that a technician would perform. I know you already replaced your regen boards but maybe there’s a manufacturing defect in one that would normally be flushed out by bench burn-in.

Hi Stefan, I have two P10s. About five years ago the regen boards were replaced in both units and I asked to keep the ‘good’ ones (only one P10 was playing up). Maybe I was given some duff boards!

Anyway, let’s hope that PS Audio have a procedure documented for testing a transformer. Kevin, the UK Distributor reckons it’ll be the regen boards rather than the transformer. If they don’t I might let Kevin take the transformer out of my P10 that’s working fine at present (but I’d rather not touch it, they seem fragile).

Dan.