My PC keeps blowing the fuse in the power lead

[grundles]

Hi everyone. I'm having a problem with my PC. Sometimes when I turn it on it will blow the fuse in the power lead. I have had the computer for 3 months and it has only started doing it. I turned it on last week, a quick split second light from the fans then the PC dies. I replaced the fuse and then it turned back on. It then worked ok for a few days turning on and off fine then this morning it did it again. When it happens I replace the fuse, it works but I have to copy a new bios from the backup as it corrupts the normal one. Any ideas what this could be?

My build:
Corsair AX860
Gigabyte 990fxa-ud5
AMD fx-8350 @stock
MSI gtx970 @stock
2x Kingston HyperX fury 8GB
TP-link wireless adaptor
Zalman CNPS9900 Max
2x seagate barracuda 2TB in raid1
NZXT sentry3
7 led case fans
ASUS DVD burner
LG BD burner

Any help would be greatly appreciated, thank you

 

[DasHotShot]

I would initially point at the PSU.

It's a good model, however it is the likely cause of the problem. Could be faulty.

Do have the chance to try a different PSU (a friend's?)?

 

[grundles]

No I don't know anybody else with a custom built PC other than my gaming friends that I haven't actually met in person lol. I would have to either buy one or chance it by sending mine back. It is still under warranty. But they will change me if it is not the psu at fault and I send it back

 

[Sapphire Thunder]

Could indeed be faulty PSU...however it also could be that you simply have too small fuse.

 

[grundles]

It has a 13Amp fuse. That's the biggest domestic fuse you can get in the UK. I use the same size fuse to run my 2Kw oil heater lol

 

[Sapphire Thunder]

It has a 13Amp fuse. That's the biggest domestic fuse you can get in the UK. I use the same size fuse to run my 2Kw oil heater lol

hmm...that's the problem then. Depending of rail, the psu gives out up to 25Amps or so.
"+3.3V@25A, +5V@25A, +12V@71.6A, -12V@0.8A, +5VSB@3.0A"

When the original died, you swapped it with too small fuse, I guess.
And the original died from some power surge.

 

[grundles]

Sorry for picking that as best solution. It wasn't the fault. I put in the same fuse as was originally in the lead. And the rails can give a higher current than the mains. This is because they're at a lower voltage, as we know power=voltage*current and as current rises the voltage can drop to keep the same power so the mains should never go over 13Amps as it is 240volts

 

[Sapphire Thunder]

Sorry for picking that as best solution. It wasn't the fault. I put in the same fuse as was originally in the lead. And the rails can give a higher current than the mains. This is because they're at a lower voltage, as we know power=voltage*current and as current rises the voltage can drop to keep the same power so the mains should never go over 13Amps as it is 240volts

Sorry, I understood it wrong from where the fuse was blowing. (blame english for not being my native language)
Your psu is probably faulty indeed.

 

[McHenryB]

It has a 13Amp fuse. That's the biggest domestic fuse you can get in the UK. I use the same size fuse to run my 2Kw oil heater lol

Nothing domestic should blow a 13 amp fuse unless it is faulty. I guess it is just possible that there is something wrong with the wiring to the wall socket, but everything points to a faulty PSU. Even if there were some other fault in the computer it should blow the fuse in the PSU rather than the one in the plug. Just one other possibility I can think of would be an intermittent short-circuit in the mains cable; that's easily checked by using another cable. (You probably have a few spare mains cables - if not, it's not a great expense.) If that doesn't fix it then I would RMA the PSU. If that doesn't fix it get an electrician to check your wiring.

Just as an aside, I would go for a lower amperage fuse in the mains cable. 13 amps seems too high, so I'd go for a 5 amp one (3 amps might be cutting it a bit fine). I don't think the 13 amp fuse is giving you the appropriate protection.

 

[grundles]

I hadn't thought of it being the lead itself. That would actually make sense with the symptoms I've got. And I think you're right about the size of the fuse as 860/240 = 3.583 so a 5amp fuse is probably more appropriate. I just changed the one that was already in for an identical fuse. I have a multimeter so I will check the continuity of my cable in different positions to see if there is a short somewhere and I will post back to let you know. I'll also use a different cable for a bit. If that doesn't solve the issue then I suppose it's the psu going back to the manufacturer

 

[grundles]

UPDATE: I tried a new lead and the same thing is happening. But I have been a bit of an idiot, the fuse in the lead isn't blowing, I just thought it was because the first time it happened changing the fuse fixed it. So this is happening to my PC and no fuse is blowing at all. Any ideas now? Or are we all still thinking psu?

 

[Sapphire Thunder]

UPDATE: I tried a new lead and the same thing is happening. But I have been a bit of an idiot, the fuse in the lead isn't blowing, I just thought it was because the first time it happened changing the fuse fixed it. So this is happening to my PC and no fuse is blowing at all. Any ideas now? Or are we all still thinking psu?

If that's so, then yes. It is psu most likely.