PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heating!?!

[socngill]

Hi. This will be a bit of a long explanation, but please bare with me!

Just over a week ago the trip switch for our front room went (rest of the house was fine). So I flicked the trip switch back on. After a few minutes there was a big bang and it went again. Turns out the power supply in my PC blew. I replaced the power unit with a spare, but that also fizzed, banged and died - although it didn't trip the switch on this occasion. I ordered a new PSU which I plugged in and it worked. Excellent. I still had the machine open as I had to move a few bits to get everything out and in safely, so, with the PC turned off (but with the PSU still on) I screwed the HDD back in - promptly followed by a flash and the PSU died. Now, I don't know if this was caused by me (would make sense, although it's never happened before) or the same underlying problem. Anyway, I sent it back and got a replacement. Plugged that into a spare machine (still in the front room) and the motherboard light came on so I knew the PSU was at least working. I did not actually switch the machine on though. Plugged it into the machine having the problems and as soon as I went to switch it on, it blew and again took the trip switch with it.

I should add that the PC is plugged into a surge protector unit and that seems to have suffered no ill effects. The circuit that feeds the PC in the front room also has a sound system, wireless router, HD TV, VM HD Box, Wii, a light, phone charger and laptop plugged into it. Obviously not all from the same extension lead!!! Somebody has suggested to me that the PSU, when switched on, overloads the circuit and causes the unit to blow and the trip switch to go. but is this likely? I've had all this equipment plugged in for 4 years. The only addition (and I personally think this may be the issue) is that when we had our bathroom refitted the guy hooked up our underfloor heating to the the same fuse and circuit as the front room. Which just seems wrong. Could this be the cause? Would it have taken circa 2 years for the issue to arise (which is about how long we've had the underfloor heating in)?

I'm going to order a new PSU, but if there's an issue with the electrics then I need to get that sorted.

Sorry for the long post, and the large amount of info but i wanted to be as precise as possible so you have as much info as possible.

oh, the PSU is only a 500w unit. So not the post power hungry unit in the world!

Thanks in advance.

 

[malcolmsanford]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

Are you prone to surges in your area? Some SPD do fry if they are activated as that is there job to protect the appliances, so can be self sacrificing. Have you checked that the wall socket the the SPD is plugged into is ok, is there any sign of burning on the wall socket faceplate.

If you have a good voltage indicator can you check the voltage in your house. There are reasons that voltage surges occur often in a domestic situation is a neutral failure on the suppliers network which can lead to over voltage, but that is something to check when all else fail.

I would try and check the socket in where the lead is plugged into first and go from there

 

[socngill]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

Thanks for the quick response. I will have a look at the socket this evening. I don't have a voltage checker but I'll have a look at how much they are and maybe pick one up.

Do you think the underfloor heating is OK to be on the same circuit as other stuff, or should it have it's own like the electric shower does?

Also, if it is an issue with surges and or voltage would it be likely that it would only effect the PSU in the PC?

Thanks again.

 

[socngill]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

Had a check of the sockets this morning and could see no problems such as burning. I will check the type of fuse in the box this evening as perhaps it could be to low? Maybe that would cause the problem?

Is it possible that there is something in the PC that's causing it? I would of thought not as the trip switch on the fusebox is going but not the surge protector that the PC is plugged into?

Thanks.

 

[telectrix]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

firstly, i think you need to have the fixed wiring tested and checked to verify circuit loading, condition of cables etc. , then, if that's OK , it's down to something plugged in.

 

[malcolmsanford]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

Had a check of the sockets this morning and could see no problems such as burning. I will check the type of fuse in the box this evening as perhaps it could be to low? Maybe that would cause the problem?

Is it possible that there is something in the PC that's causing it? I would of thought not as the trip switch on the fusebox is going but not the surge protector that the PC is plugged into?

Thanks.

I'm sorry i miss read your OP. I thought that you tried PSU's into 2 computers which you did, but you then removed the PSU back into the original Comp and it blew so it is just one computer blowing these PSU is that correct?

If that is the case then yes I think it is the one computer that is causing the problem.

 

[socngill]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

I'm sorry i miss read your OP. I thought that you tried PSU's into 2 computers which you did, but you then removed the PSU back into the original Comp and it blew so it is just one computer blowing these PSU is that correct?

If that is the case then yes I think it is the one computer that is causing the problem.

Yes, that's kind of correct. When I tried it in the spare machine I didn't actually try and turn it on and load it up. I switched the PSU on and saw the light on the motherboard came on to show that the PSU was working, I then switched it back to the main PC where it blew when I tried to start the computer. So as I didn't turn the machine on there would have been no power load being drawn from the PSU and thus the fusebox. So I think I may need to actually switch on the old machine when I get a new PSU and see what happens before trying it again in the problem one.

Think I might take the whole machine and put it back together again in case anything is shorting the board.

 

[grantr37]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

buy a new IEC lead as well, make sure that the selector switch is on 220v if it is a manual selection one (i.e not an automatic switched mode selector power supply that does this itself) also if you still have the old power supply units that blew up, can you unscrew the metal cover and take a photograph of the insides to put on here, from that I will be able to see which parts have burned so that I can see where the problem is and tell you.


Thanks

 

[socngill]

Re: PSU keeps blowing & tripping fusebox - same fuse/circuit as the underfloor heatin

Finally got a decent replacement psu, but all I get from both boards is a half second movement in the fans and then nothing. So I think the experience has damaged both motherboards - the old one was knackered anyway. Pain but think u may need to buy a new mobo.

Thanks for your help.