> One of my P9 cases has a noisy PSU3. The other four PSU3s are
> silent so it’s not normal. Are replacement PSU3s available Or
> even just the toroidal (I’m an electronics engineer so easy to
> replace it myself.)
>
> Thanks
> John Hollis

Hello,

both PSU are available as spare parts (also the PSU2).

We would like to see the noisy PSU3 to find out what's wrong. From your
message I cannot see where you ordered the A-100P9 and what's your home
country. If you are within the EU we could exchange the PSU3 for free (or
replace it by an A-100PSU2 for free). Outside EU please contact the dealer
where you purchased the unit.

As actually all PSU3 are the same I'd recommend to check if the noise is not
generated by one of the modules installed into the case.

Best wishes
Dieter Doepfer