PSU stops working after WOL

Hardware PSU
1

I have a FreeNAS box with a Seasonic s12g-450 PSU that has been working fine for 2 years. I have WOL set up on it and had no problems until about a month ago when I had a power failure and it wouldn't start with WOL. It seemed somewhat possible that the power failure was to blame and that it needed a manual start, so I did it and forgot about it.

Yesterday I remembered and decided to test WOL again. I shut down the machine, then tried WOL and it didn't work. I then tried to start it from the power button and that didn't work either. I took the PSU out, shorted the 15 and 16 pins and still nothing. After about an hour, I tried to short out the pins again and the PSU would start for a few seconds then stop. I left it for a few more hours and it seemed to start up fine. All the voltages seemed fine as well. I stopped and started it a few times to make sure, then put it back in the NAS, which also started up just fine.

Finally, today I decided to see what the WOL thing was all about, so I shut down the NAS and sent it a few WOL signals. Nothing. Then tried the power button and again nothing.

I already made an order for a new PSU, but thinking about it I'm starting to suspect the motherboard. Maybe it overloads the PSU somehow on WOL and the PSU needs a few hours to empty its capacitors before it works again? If that's the case, I'd like to cancel the order for the PSU because returns are a bit of a hassle over here. I'd rather not take apart another PC to test components one by one.

Anyone have any ideas about what might be going on?

2

Update.

I tried another PSU in the NAS and it works fine, WoL included.

Then I tried the suspect PSU in another PC and it also works fine, WoL included (after i let it drain again).

The suspect PSU in yhe NAS still behaves the same. It works until I try to use WoL. That fails. If I retry a few times, it locks up and the PSU stops working altogether for a while.

Let me restate that this hasn't always been the case. WoL worked just fine on the NAS with that PSU until a month ago.

Anyone?

3

If its allready an older psu, then upgrading it at some point never really hurts.
If the system just shuts down, then its probablly a psu issue indeed,

4

2 years of pretty much 24-7 uptime may be a lot, but it's a pretty good PSU. It also works just fine if it's in the other PC.

I'll probably get the new one anyway, but at this point I'm more curious about what's happening than anything else.

5

Yeah allways hard to tell without some decent diagnose.
Could be psu or motherboard maybe.
Only thing to trully find out is replacing one of the two.