Trouble installing new PSU - blue sparks, bangs, help!

**econ21** · 02-03-2007, 23:44

I need help! I've tried to install a new PSU on my computer and it worked fine the first time I ran it after installation. But then I put the lid back on it and it was unresponsive. No lights, no sound.

As the problem arose after putting the case lid back on, I thought I might have loosened a wire or something pushing the thing in. In particular, the wire connecting the front power button to the innards might have come loose, so I pressed that in. I also switch the amp on lead from 5A to 13A (as the new PSU says 500W 8A). I switched on the machine and there was a nasty blue flash from within the PSU and a small bang. Whists of smoke and pungent smell.

Waited a while, tried with another lead (5A this time). Another even nastier blue flash and a louder bang. More smoke, more smell.

Anyone got any advice? (I rather suspect "step away from the machine, you're an idiot" would be in line, but still...)

The background is that I am trying to upgade my 250W PSU to a 500W PSU, as I've belatedly realised I don't have enough power for my 7800GS Geforce card (manual says it needs 350w+; only yesterday I realised I had just 250W). Installation seemed to be straightforward - just plug in the connectors to the processor and appliances - so I am not sure what's causing the current nightmare.

This continues the saga of my overheating PC:

https://forums.totalwar.org/vb/showthread.php?t=78720

I realised my computer cutting out could be due to the overheating or insufficient power.

On the overheating, I followed the hunch of my manufacturer's tech support that it was a problem with the PSU fan. So I cleaned the fan, removing a layer of dust between it and what looks like a heatsink. After that, the temperature on booting was around 38C, rather than 65C. So that's the good news.

The bad news is that I can't solve the power issue. I thought upgrading the PSU would be easy, but now it looks like I will have to put in the old PSU and maybe old graphics card if I can't figure out what's wrong.

My computer's still under on site warranty and the supplier is sending someone out to look at the heat issue (although that may now be solved). I could just pass the whole thing over to the repairman, but I suspect if I leave the upgaded components in, the warranty will be void. I could put back the old components, although effectively that means having wasted a lot of money on the top-end graphics card and PSU.

Any advice?

**lars573** · 02-04-2007, 00:47

Your new power supply has blown up on you. Cause those symptons are textbook "this baby is cooked!" That kind of behavior screams defective. And by lead you mean fuse?

**econ21** · 02-04-2007, 00:51

OK, I've been thinking the best policy is to go back to the store I bought it from (PC World). They offer a £30 upgrade installation service - maybe I should just put it in their hands? (My nerves are a little frayed after the two blue flashes).

**sapi** · 02-04-2007, 02:01

That might be the best idea - that way you can blame them the next time something blows up

**Xiahou** · 02-04-2007, 02:21

Hopefully the power supply didn't destroy any components other than itself.

**sapi** · 02-04-2007, 02:22

I was thinking the same thing. If you accidentally hit the wrong thing.... :(

**caravel** · 02-04-2007, 03:37

The PSU is indeed "toast". There are some large transistors on the main board, if you hear a bang it's one of those. Bigger bangs with blue smoke and a horrible smell indicate that one of the larger condensors have "popped". In my experience PC World are a bunch of ....... You may have difficulty getting an exchange/refund, though hopefully not. What brand of PSU was it?

As the problem arose after putting the case lid back on, I thought I might have loosened a wire or something pushing the thing in. In particular, the wire connecting the front power button to the innards might have come loose, so I pressed that in. I also switch the amp on lead from 5A to 13A (as the new PSU says 500W 8A). I switched on the machine and there was a nasty blue flash from within the PSU and a small bang. Whists of smoke and pungent smell.

You say you may have loosened something. Connecting the power, hdd, speaker, etc jumpers to wrong pins can be disastrous. That could have been the cause, also I'm not sure why you switched the fuse, but I doubt that had anything to do with it. Once a PSU or the kettle lead fuse has blown though, it is inadvisable to try and connect it again. Hopefully your motherboard hasn't been damaged. Before you reconnect your old PSU you need to be absolutely certain that everything is connected ok inside, if you're unsure of what you're doing, you should defininitely get help.

**econ21** · 02-04-2007, 10:55

Thanks. I've put the old PSU back in and everything works fine, so the new one going bang thankfully does not seem to have fried my computer.

I did worry I'd connected things wrongly, but I've just plugged the connectors in the same way with the two PSUs, so it's not clear how I can successfully install the old PSU twice and yet blow up the new one. (I suppose the new one might need connecting in a different way, but this wasn't clear from the instructions or physical appearance of the thing).

BTW, the new PSU is a jeantech 500W - it's the only brand PCWorld sell, although I bought the most powerful (for the bigger...err...bang

)

I think I'll try to get a refund from PCWorld and make an appointment with them to install a new one.