RESOLVED! -P20 no longer wants to Initialize

I have been having issues wit P20 Shutting down when the preamp owers up the Monoblocks during this cold snap. I have been powering one amp separately since charging capacitors of both with 20 milliseconds stagger was still too much for Instantaneous draw. Tonight I forgot.

Usually P-20 will recover on its own with power cycle. So far the rear 20 amp plug pulls and power cycle has not helped. Nor holding front switch while flipping on the back panel switch.

Symptom. The second the P20 leaves initialization screen where it should show the duplex banks the screen dims and you can hear it pull power to the transformer . I will leave it unplugged to see if it is just power grid issue as temperatures are dropping again and everyone heat is likely dragging things down. I tried the 15 amp iec input and same performance.

Hoping it is a quirk and it will power back up after a long cold soak.

Open to any suggestion on things to check to get it going.

P.S. Other than order a Puritan. @weedeewop


The culprit is the SR Master fuse!

Sorry, I couldn’t resist the temptation!

Kidding apart, I had the same issue with a brand new P15 last summer. It ended out being a board issue. Does the display stay on showing the socket symbols or it goes dark?

If power cycle doesn’t work, you may try open the lid to check if the board and connectors are well tighten or loosen a bit. Remember to pay attention to residual electrical charges before touching the inside parts.

Another test should be a software update by SD card.

A call to PS staff is the best thing, though.

Good luck.


Can’t hurt to try a Puritan or two. Won’t solve low voltage issues, but you know that. If you really are experiencing low voltage or worse a brown out I’d unplug things for the time being and read a book. BTW I do have a P15 around here somewhere.

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The Display goes dark. Was that your symptom? I have never flashed firmware on the unit. Do you recall which board was the culprit on your P-15?

Its not a good time to start lifting a P20 in a shipping box for me. My back surgeon still has me on restrictions. Plus all my top notch cables won’t reach all the equipment from my 4 dedicated 20 amp lines. I may have to play musical cable games with the reserve cables. I hate what moving cables does to the dielectrics.

That 300 hours with the SR Master Fuse was like 21/2 weeks with a painful hemorrhoidal flare up waiting for something to improve but only a master-fuse-ectomy could solve it . Perhaps the P-20 experienced a life shortening experience from it?


Let me check my old emails with PS Staff, I should find the instruction received for the board (P15 in my case). I’ll send you a PM soon.

Symptoms: initially it was stuck (display on) and every 3 minutes I heard the “click” from the inside but without switching on. Then, after a few times I was trying repeating that, the display went permanently off, still every 3 minutes the “click” from the inside. No ways to be able to power on the unit.

Once I replaced the board, the problem was immediately solved.

I know, moving around that beast is not a joke.

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My cold soak over night did not work to revive P20. Same exact symptoms. Next I will try P20 troubleshooting documents Luca had in his email from his regenerator issues that he received from PSA support. Luckily it states P20 and has internal photos of the card connections. I will also try a firmware reflash, if I can find an SD card with the shipping box in the attic.

I also need to find that ever elusive SD card slot in a blind install. :frowning:


Damn, I’m so sorry you’re having these issues with your P20.
Surely the low temperatures do not help the electricity company to provide a linear and disturbance-free energy source but whatever happens, I would immediately contact PS Audio and try to send the unit, if possible, to their laboratories.

Stupid question: :joy:
how do you open the lacquered MDF top plate?

There are four corner allen screws. You remove then lift up with a suction cup or grab rear of the cover and tilt forward. If you follow the link in my profile it explains some great performance RF absorption tweaks of the P20 and cable and fuse trials.

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Thank you for the tip! :wink:

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Thanks for the oscillator board troubleshooting info. As I figured it was firmly seated. Also firmware reload off SD card froze The P20 has 3 years and 11 months. Maybe it’s telling me I need two

I reached out to support looking for options besides shipping unit in since boxing it up not an option while on lifting restrictions . Such as ship the oscillator board to them or procure a replacement for self install.

Once We have a path forward I will decide whether to start a direct to wall plugs solution. It is pretty quiet here with only a bedroom system with less horsepower


I really hope you can fix it as soon as possible with a board replacement sent to you. Good luck.
Going temporarily straight to the wall should clearly demonstrate the P20’s virtues.

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I got to chat with Caleb in PS Audio service. Based on watching a video of the symptoms he noted that the P20 sometimes remembers the event where it last shut down. Thus a restart or restart with the blue front panel standby button will keep it from the next step in the boot up cycle.

The key after initial initialization screen it goes dark. He said wait until you hear another solenoid click about 15 to seconds later. After one hears that click. Press and release the front panel standby button. This in turn over rides the protection mode memory and unit will power up.

That cured my issue. It is curious that after dozens of protection modes in the past four years . This is the first time I encountered this phenomenon.

Thanks Kudos to Caleb and PS Audio Service Department!


Glad to know!

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This is great to know.

@aaronm @jamesh : I hope I don’t seem unduly critical by noting this should be added to a punch list of things to improve upon with the latest generation of PSA Regenerators (if not already done).



The unit was just protecting itself from the last event stored in its memory. Why it didn’t react the same way previously on my recovery is curious. Not sure if this wouldn’t be an intended feature. I am happily sharing having avoided an equipment return or repair


Dors this work on alll regenerators?

Not sure if it applies other than P15 ans P20 that share firmware.

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It worked on my P10, that I thought had died. It was dead on Sunday when I got up, tried turning the switch at the back off and on and it would istart to initialize, make a clicking sound and then shut down. Found another thread and followed the suggestions there, but to no avail. Tried what worked for Vmax and I’m back in business.



I am happy I shared!

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Me too!