[zAy0LfpBZLC8mAC]

Yes, a noop and declaring the "test" successful.

I would be very surprised if you could find any non-ancient (and I really mean ancient, like, pre-PC, probably even pre-home computers) computer PSU that you couldn't feed with DC. What voltages will work will vary, but as long as you stay below the peak voltage corresponding to the effective voltage printed on the label, you probably won't damage anything.

If you really want to test it, you could measure the resistance at the mains input, if that gives you a non-infinite value that stays at that value (rather than increasing towards infinity), you are dealing with a mains transformer. But you really won't find that in a computer PSU.

[xxs]

~240V fully rectified to DC is 340V. Since AC varies it's safe to say virtually any PSU that's not exclusively Japan or North America will take 350V DC.

[namibj]

Thanks!

It's a hot-swappable 300-1897 (aka X6328A aka Type A217) 1050W Sun PSU. I'm primarily worried about the active PFC I expect in it.

Is there a way to test such a PSU without risking the entire server? (save for taking everything out that isn't needed to post into BIOS)

[zAy0LfpBZLC8mAC]

Well, you probably can somehow power it up without a server connected to it?

Active PFC tends to be simply a boost converter at the input stage that boosts the (rectified but still unfiltered) input voltage to (DC) 350 V or more, modulating the current to follow the mains voltage and should generally have no problem with DC input, especially so with wide-range inputs that have to be able to deal with different voltage levels anyway.

[namibj]

>modulating the current to follow the mains voltage and should generally have no problem with DC input

I'm particularily worried about confusing that following/regulating circuity. If the 50/60Hz it senses are caused by screen refresh feeding back somehow, it might end up behaving "weird".

But I guess I'll just try, and hope it won't break anything.