PSU blew up, what now?

Corsair HX850i , i bought it used and had no problems for half a year till now.
Out of nowhere, while flipping the switch on the cable, a loud Bang and sparks from the mains part of the PSU -> the circuitbreaker tripped.

I run a custom loop and i had water stains on top of it, after the last drain-action.

Because it was used, and the stains on it, i thought that i was to blame and took it apart.

Here is the problem, no water or stains inside, nor burnmarks.
I don't know what the fuck happened.

Any ideas ?
Bets on what happens when i plug it in again ?

Thx Rage.

Blown caps? Cylinders with the top split or plain not there any more. Maybe just a small leek in the cap would ooze out the goop and maybe cause a short?

Shit stains. Look for brown marks on the PCB of the PSU. Be careful pokeing around. Could still be some charge in some of the caps. Short those with your hand and you could get a nasty shock.

Got a multimeter with continuity check mode? Also pictures. Let's have em.


you want pictures ? You'll get pictures!

No shitstains or any other clue that i found in staring at it for 20 min.

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had a same issue w/ 3 corsair products. lets just say i dont use them at all until they fix their shit

Yeah I think we need to see under the PSU. Maybe some water dripped down the side and fell into the pan at the bottom?

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This. Many PSU's require you to desolder stuff to completely remove the PCB, however, you should be able to get a view of the underside by unscrewing the screws holding it in.

It's probably more than likely that one of the main switchmode IC's or a cap blew its ass. Those are normally the things to catastrophically fail.

Hard to tell but... bit of discoloration and some deformation of the heat shrink ?

@recoil44 thx for pointing that out!
I can't seem to find the cause of that though.

@all its late here , and im struggeling to get the pcbs out of the case, so i guess that ill return tomorow with better tools and more pictures.

Thx to you all so far!

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Corsair really dropped the ball on these. Whoever they had make them uses shit parts. Don't fix, burn and get a different brand. These fail at a high rate.

RMA the thing?

Johnny Guru did a review of the 750 model with a bunch of disassembly pics:

and more at the site. He gave it really really high marks.

I never owned a PSU that cost more then 30 bucks so I can't help much. I would not know what to do with a 150 to 200 dollar PSU. Wish I could help more.


small update on what i did and figured out over the last few days.

RMA, is not an option as far as i can see, because i broke the seal to take a look inside and i bought it used and corsiars waranty isn't transferable.

So RMA is dead except if corsair is very nice, but considering that i can probably only reach the 0815 custommer supporter, i highly doubt that.

I took it apart, checked everything for visual defects, and found nothing.
Put it together pluged it in and this time i could see where the arc jumped.
painted a blue arc where i saw it.

I guess its toast.


If you can solder, replace it and save some cash.

Example (note I do not know if this is an exact replacement, you'll have to do some digging into specifications):
Jameco Electronics

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If it really is one of those main filter caps that went faulty, that is a super easy and cheap fix. It makes no sense for you to just give up, especially when you're fairly certain you know what the problem is.

@TheAlmightyBaconLord @recoil44 thank you both for the motivation.

from my point of view, the arc / spark came from below the cap. That means that here is something conductive below it or that there is a sparkGap of probably a 1 cm.
1cm sparkgap means a pretty high voltage.
The Bang the spark made was seriously loud, and my right ear felt a bit of pain thrrough the rest of the day.

But the high-voltage idea is also controverse, because at some point it should have gone through the cap and not through the air between the pins.
The max voltage of the cap is probably lower then what it takes to bridge a cm of air.

The first "bang" incident wasn't that cap! And it blew the saftey which this time it didn't.

So i guess that its something else in the circuit and that just caused the spark at that cap.

Away from that topic though.

I am not willing to poke around and measure whats going on in the psu while its pluged in and hot / live.
I'd probably be dumb if i did!

Meaning that this will be a try and error game of desoldering a few parts, pluging it into the wall, probably getting deff from the bang, and then rense and repeate!

eat, sleep, rave, repeat
desolder, turn on, get deff, reapeat
disclaimer, i dislike the music.

The next steps that i will take:
Desolder stuff from the PCB to seperate the mains part from the rest. I don't want to damage that accedentaly.

And take of that cap with the hope that something is below it even though i doubt that!

Any ideas for after that?


Took it apart again and i hope that i have a better picture this time.



Does corsair hand out schematics or information about that stuff at all ?