Question PSU clicks off a second after turning on.


May 25, 2020
I had a Seasonic FOCUS GX-550W PSU powering a new system I build with a Gigabyte AORUS X570 Elite Wifi Pro motherboard, a Ryzen 5 3600, 64GB DDR4, MSI GeForce GTX 1660 SUPER , 2x M.2 nVME drives and a 5 SSDs (phanteks Eclipse P500A case). This worked beautifully for 2 years, until last week when I heard a loud pop and flames shooting out the PSU. It was connected to a battery-backup / surge protector so I'm not sure why it failed since there was plenty of power headroom already... but it did. And a horrible smell. Ok.. blown caps. So I purchased a new Corsair RM650x. Way more overkill for my system but I wanted room to grow.

When I power the system on, I see an LED (LED is not on the MB... it's on a tiny box I believe was initially intended to light LEDs on the case but was never used).... that LED comes on for half a second and then powers off. I hear a click on the power supply (like a relay switch) as it switched off. 'not sure where do go next? Try again with no drives connected (just nVME boot drive) and one memory stick? Are there some test points on the MB I can probe? I did not measure the voltage on the PSU connectors since they usually require a load to power up? How much of a load? I can put resistor across the terminals and measure the voltage?

Does this mean that the Seasonic PSU blew my motherboard? CPU? Memory? Bad PSU? Any debugging steps would be appreciated.



You're using the cables that came with the Corsair RM650x right? You're not using cables from the Seasonic on the new PSU?

Yes the when a PSU fails like that, flames and smoke and smell of ozone and all it can kill other components like the motherboard. I'm not saying this has certainly happened as the ols PSU has protection mechanisms and should have protected the components connected to it.
Reactions: keith12
Hi EdLandau. I'm sorry to hear about your recent PSU failure, and the potential resulting damage to your other components. I'm honestly not sure where to start with troubleshooting your problem. But with that said, I would recommend that you open a RMA with SeaSonic ASAP. I have very little doubt that they'll provide you with a replacement PSU. And I think there is a chance that they may reimburse you for your damaged parts. What I don't know is whether or not you should volunteer that the system was connected to a battery-backup / surge protector. On one hand admitting it was may support your case that the PSU was at fault. On the other hand, I wonder if the PSU and battery-backup manufacturers would play who-shot-john and point the finger at one another. Were it me, I don't think that I would volunteer the backup unless they asked if you had it. If so then tell the truth and see what they say. I wonder which of the two are responsible. If other components did indeed become damaged from the PSU's protections not working then I would assume that the responsibility lies with SeaSonic. In addition to keeping this message thread updated, I recommend that you contact SeaSonic ASAP and explain what happened. They should be able to help you troubleshoot if the PSU damaged the rest of your components. If they initially only approve of the RMA because they want to verify that your parts are indeed damaged then ask if they'll expedite the replacement. It doesn't hurt to ask.

Sorry for the verbose response. I received very little sleep last night, so my mind is rambling a little bit. Good luck and let us know how it goes. Perhaps someone here might have a better suggestion than mine.
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