Repairing a Corsair HX850 Power Supply?

[Xtreme2damax]

I have had two Corsair HX850 power supplies fail on me with the same exact symptoms and issues. At first the system will start rebooting or shutting down at random, reboots happen regardless of what I am doing whether I am in the bios, running a memory diagnostic, running a Linux live disc etc.. most of the time the reboots would occur while attempting to log into Windows when there is significant power draw on the PSU. Stress testing won't trigger an immediate reboot so I can even run games for hours sometimes and the system can be up for as much as a few days to a week without rebooting. Then comes the second and final phase which is complete failure as in I start experiencing trouble posting and then I can no longer power on my system.

When my last PSU did this I was forced to purchase a new PSU from Newegg due to the warranty being voided, I purchased the same brand and model as I did before. The previous PSU and the replacement both ended up failing with the same exact issues and symptoms around six to seven months of use. Last week I shipped the replacement PSU back to Corsair corresponding an RMA request and am hoping to receive the replacement within the next two weeks (for now I am using my roommate's computer), I still have the original PSU that I've kept down in the basement since it failed.

I am in a situation now where I can't afford to purchase new hardware should I keep experiencing this issue with the Corsair power supplies. I don't think the PSU's are completely shot, just that they have a defect that is causing these issues. I am wondering if it is possible to repair the original PSU and how complicated and/or expensive would it be to repair? I need to have something as backup as I don't trust that the next replacement won't have this defect and am afraid I'll be in the same boat again six to seven months down the line.

[Blaze_Zewi]

Openning up a power supply and trying to fix it yourself is a bad idea. You chould end up destorying your entire computer or worst get yourself electrocuted.

Go with a different brand of power supply in the near future. Hiper, Antec, Rosewill, Thermaltake etc... Lots of good brand name to chose from.

[xendrome]

^Not to mention I wouldn't ever 100% fully trust a repaired power supply...

[TEX4S]

Ya know how when youre watching a horror flick - and the killer is behind a door, and the hot chick is about to open that door ? And you think "dont do it, dont do it " ?

Then she does it and bad things happen ? Thats what I think when someone mentions opening a PSU.

It is strange that 2 Corsair PSU went bad, showing the same signs - go with something different this time...

FWIW I just bought a Seasonic Platinum 1000W after owning a Corsair AX850 - couldnt be happier

[Dot Matrix]

Rule number one: DON'T.

[linsook]

how are you so sure its the psu?

[Another Canuck]

how are you so sure its the psu?

I second this.

If it keeps happening over and over again, how do you know it's the PSU? What diagnostic steps have you taken to rule out other components?

A system that is randomly rebooting can be caused by any number of things, including unstable grid power. Personally, the PSU is one of the last components I would consider here.

FWIW I just bought a Seasonic Platinum 1000W after owning a Corsair AX850 - couldnt be happier

You had the AX850 for seven days :laugh:

[TEX4S]

You had the AX850 for seven days :laugh:

ssshhhhhhh :shifty:

Well, uhhhh, true.

[+Biscuits Brown MVC]

I second this.

If it keeps happening over and over again, how do you know it's the PSU? What diagnostic steps have you taken to rule out other components?

A system that is randomly rebooting can be caused by any number of things, including unstable grid power. Personally, the PSU is one of the last components I would consider here.

You had the AX850 for seven days :laugh:

....and that AX850 was made by Seasonic (as are the ones the OP has)... :shifty:

[monkey13]

Never, ever, ever, ever open a PSU. There is serious danger in there. First there is the chance of straight out electrocution. Even if it has been off for a while there is still a fair bit of capacitance in there.

Second it is also a major fire risk. Bodge something in there and your whole PC, plus possibly you house, could go up in flame.

Also there are as near enough zero user serviceable parts in there. So there is nothing you can fix anyway.

[muratoner]

the caps must have been dried..just open the power supply lick the biggest cap :)

PS..seriously DON'T!!!

[Xtreme2damax]

I second this.

If it keeps happening over and over again, how do you know it's the PSU? What diagnostic steps have you taken to rule out other components?

A system that is randomly rebooting can be caused by any number of things, including unstable grid power. Personally, the PSU is one of the last components I would consider here.

You had the AX850 for seven days :laugh:

Last time this happened I was able to eliminate other components as the culprit and finally determined the PSU was the cause of my issues. When I bought the new PSU and hooked it up everything powered on instantly and the system posted, no reboots or shutdowns unless I manually initiated a shutdown or reboot myself and everything ran stable. Then six to seven months down the line I ran into the same exact issues again and I am fairly certain the PSU is at fault again. I'm pretty sure nothing else in my system is at fault, there are no shorts and when the system shut down or reboot it's as if the system was losing power. On the Corsair forum there are other people with the same PSU and other makes of Corsair PSU's experiencing the same issues, and like some of them I have an Asus Sabertooth X58 motherboard. :/

I live in an apartment complex that is around 20 - 30 years old so who knows maybe the wiring here is an issue and dirty electricity is being fed into my reletively cheap surge protector I have everything hooked into. Although I don't see why only the PSU would fail and nothing else. I had my system overclocked to 4.2 Ghz, everything was reletively stable and temps were low enough not to be an issue, I rarely ever shut my system down or rebooted mainly because at the time I was using my system as a game server.

Never, ever, ever, ever open a PSU. There is serious danger in there. First there is the chance of straight out electrocution. Even if it has been off for a while there is still a fair bit of capacitance in there.

Second it is also a major fire risk. Bodge something in there and your whole PC, plus possibly you house, could go up in flame.

Also there are as near enough zero user serviceable parts in there. So there is nothing you can fix anyway.

I understand, but what if the issue is as simple as loose connections or loose solder joints? When I opened the last PSU to inspect it there were no bulging capacitors and nothing was burned out or blown.

[Alwaysonacoffebreak]

I've worked in electronics for a while and I've tried to do the same thing what You are planing to do (keep in mind I've had all the neccecary equipment for that) and belive me if I say, don't bother. Won't do You any good, the last one I opened and fixed..well lets just say the HI-POT test wasn't too sucseful after almost burning the box to the groud.

[Xtreme2damax]

I have an SLI system and someone mentioned to diable SLI if I overclock because it causes dangerous voltage spikes. Is this true, I don't see why overclocking and enabling SLI would do that as several people overclock and have SLI enabled without their PSU's failing like this..

[monkey13]

I understand, but what if the issue is as simple as loose connections or loose solder joints? When I opened the last PSU to inspect it there were no bulging capacitors and nothing was burned out or blown.

Don't bother. It is dangerous and if you get it wrong there are a number of bigger consequences. As an example you could short to the earth and electrify your whole pc when you turn it back on. Which could fry everything in it and/or electrocute you. Would cost a bit more to repair than just a PSU replacement.

It is never worth it. Even if you have all the correct equipment I still wouldn't do it. You have to think of everything in the PSU as mains side. Would you start messing about with your consumer unit (all right I know the CU is much easier but just an example) or your mains meter?

[Xtreme2damax]

Ah, ok but if this happens again I will be going with another brand of power supply. I will also be carefully inspecting everything before installing the new power supply.

Is this true at all, what I mentioned in my last post?

I have an SLI system and someone mentioned to diable SLI if I overclock because it causes dangerous voltage spikes. Is this true

I have my system overclocked to 4.2 Ghz, voltages were manually set in bios and within safe range and temps were fine. Another thing is it a coincidence that my problems didn't start until after I tried enabling Load Line Calibration and setting CPU Differential Amplitude to 800mA?

[mduren2445]

I have a garanteed fix for this problem but you will have to follow my instructions carefully --- go to your favorite computer parts website and order something you can afford -- obviously cosair psu's and you don't agree and if you open the failed one up and try to repair it and it takes out your motherboard, cpu , hard drive and so on you will see a new one would be a lot cheaper. BTW do you use a surge protector on your computer?

[Xtreme2damax]

Yes I have a surge protector, a cheap one that I think I paid $20 - $30 for but it's a surge protector. I'm not so sure about the wiring in our apartment complex though, I haven't bought another brand of PSU to confirm whether it's the PSU or something external contributing to the failure of my PSU.

[monkey13]

I have an SLI system and someone mentioned to diable SLI if I overclock because it causes dangerous voltage spikes. Is this true, I don't see why overclocking and enabling SLI would do that as several people overclock and have SLI enabled without their PSU's failing like this..

I don't think you would get voltage spikes. I would have thought that would remain reasonably constant. It may be possible to have a current spike if you have a load of stuff that ramps up its power requirements suddenly but then the PSU and wiring should be rated to handle something like that.

However if you are OCing then I'm not so sure. I don't know much about that.

Generally most PSU problems are because they aren't supplying enough power or the correct consistent voltage.

[TEX4S]

....and that AX850 was made by Seasonic (as are the ones the OP has)... :shifty:

I know - but now its all pretty silver and says 1000W Platinum on it - and everyone knows that silver makes it go faster. :rofl:

[Witt3439]

One thing nobody has addressed is that, from the symptoms you described, I'm wondering if the PSU is actually to blame (especially 2 of them doing similar things).

The last time I had a system doing something similar to what you described, the motherboard was shorted.When I'd swap PSUs out, it would work for a little while and then it would start rebooting on it's own. It's not going to be simple to do, but if the replacement PSU does it, try that same PSU in a different system if possible.

Otherwise, NEVER open a PSU. They can hold a substantial charge, even if unplugged for a while.

[Xtreme2damax]

One thing nobody has addressed is that, from the symptoms you described, I'm wondering if the PSU is actually to blame (especially 2 of them doing similar things).

The last time I had a system doing something similar to what you described, the motherboard was shorted.When I'd swap PSUs out, it would work for a little while and then it would start rebooting on it's own. It's not going to be simple to do, but if the replacement PSU does it, try that same PSU in a different system if possible.

Otherwise, NEVER open a PSU. They can hold a substantial charge, even if unplugged for a while.

Six or seven months between failing seems too long for it to be a short, the PSU would have probably failed before then. I've checked everything and nothing appears to be shorted, the motherboard is on risers as it's supposed to be and nothing else appears to be shorted. The last time this happened I checked everything to ensure there were no shorts causing issues with the power supply.

[Another Canuck]

I would recommend two things:

1. If you have any spare components, swap them out and try the PSU with them. Or install it into a different PC if possible.

2. Plug it into a different outlet, preferably one on a completely different circuit. Don't use the same surge protector.

[Xtreme2damax]

I would recommend two things:

1. If you have any spare components, swap them out and try the PSU with them. Or install it into a different PC if possible.

2. Plug it into a different outlet, preferably one on a completely different circuit. Don't use the same surge protector.

I don't have any spare components and I've already tried a different outlet but not a different surge protector since I don't have one. This problem, if it happens to be an external source contributing to the failure of both PSU's is going to be difficult to diagnose especially if everything is running fine and stable for at least six or seven months. :/

[Xtreme2damax]

It was indeed the power supply that failed again. I received my replacement from Corsair yesterday, installed it in my PC and everything is running fine.