PC broken down for 2nd time, need diagnosis

[johnjuliusparker]

Hello all,

So my computer has broken down for the second time but I'm not quite sure what component is the cause. I'm going to mention all the little details as well cos I think they'll be relevant.

I built the computer back in April with the following specs:
CPU: AMD fx 4100
Motherboard: Asus m5a97 pro
Ram: 2 x 4gb corsair vengeance
Main GPU: Asus gtx 560 non ti
Other gpu: some £25 one
Psu: 700w ocz stealth streams
OS: win 7

I initially bought the cheap GPU, but then got the main one. Cos I didn't like to have stuff lying round, I put the cheap gpu in the second pcie slot in the motherboard, next to the main GPU in the man slot.

Everything ran pretty much perfect. However, I did occasional buzzing sounds from the PSU.

Also, when watching YouTube vids, sometimes the screen would go purple, and I'd have to restart the computer. I looked online and read that turning off the hardware acceleration thingy might sort the problem out, which it did.

So up until mid September, nothing else really happened. I'd use the computer every day, shut it down after I finished with it and I'd only occasionally play games like cod, crysis, so I was hardly pushing the computer to the limit.

Suddenly, in one particular dark and gloomy mid September day, the computer did not turn on. What would happen is, I'd press the on button, then only the CPU and PSU fan would spin for a fraction of a second, probably a quarter of a second. No other lights would turn on on the motherboard, besides the constant led that shows the motherboard is receiving power. Pressing the power button for the second time would do nothing. I'd have to turn off and then turn on again the PSU to make it spin again. I tried re-plugging everything again but that didn't change anything.

Here comes the messed up part. After running round for a week trying to find someone who'd look into it for free, I found someone who could test another PSU. So I went there and they tried - and this is important - a CRAPPY CHEAP PSU on the motherboard, and the computer booted fine. I can't remember if they used every single CPU and motherboard power pin, I think they did.

At this point it looks like it's definitely the PSU, so I order another high end PSU, corsair 600w I think it was. At the same time, I go all the way back to Manchester with my PSU to get it returned in Aria. I go there and they test it, turns out it works completely fine for them, both with the voltage test thingys and plugging it in a computer. The guy tells me it must be my motherboard.

I return to Sheffield. I get my new PSU. I take the risk, I open it up and plug it into the motherboard... again the same thing happens, CPU spins for a tiny bit and then stops.

So from here I'm thinking wtf. A crap PSU works but not a proper one.

I take it to another computer shop. The guy sees that I've got 2 GPUs. He takes out the main one cos the crappy PSU that he wants to test the motherboard with doesn't have the pcie power. So only the £25 gpu I in the x8 pcie slot.

He turns on the computer, the computer work fine.

Then I ask him to use my ocz PSU. The computer works fine.

Just to make sure, I put the £25 GPU in the main slot with the OCZ. The computer doesn't boot.

Then I tell him to connect the crap PSU again, and using the main slot. The computer boots fine.

So, using a crap PSU I can use both x16 and x8 gpu slots. When I use a proper PSU however, I can only use the x8 slot.

I take the computer home, put in my main GPU in the x8 slot, connect the ocz, and the computer works fine.

In my mind I was thinking the motherboard was broken, but also that it was the PSU that was destroying it.

So through October and beginning of November, no problems. This time however I kept one side of the tower case open for ventilation, and I kept the computer turn on overnight for most days, rarely shutting it down.

This time when the computer broke was when I just finished browsing the web. I then started moving the mouse around on the desktop, the computer couldn't handle it and the screen froze. I observed the unlit LEDs on the keyboard and the mouse which were connected to the tower usbs, as well as the massive screeching sound coming from the speakers, also connected to the tower.

The keyboard obviously wasn't working. Tried pressing the on and reset button nothing. Tried holding the on button, nothing. I then turned it off using the PSU switch.

Turned PC on again, memok light flashing. I hold it but it keeps blinking at the same rate. Turn off.

Turn on but with 1 ram stick installed. PC boots fine, so I turn off.

Try ram stick 2, memok light flash, no boot.

Try ram stick 1 again no boot.

Reconnect all the wires and everything, nothing.

So right now, one of my GPU slots is sort of broke and either the ram slots might broken too or both ram sticks might have died together. And it might be the PSU which is killing everything off. Maybe.

I'm currently in the process of returning the motherboard, hopefully its broken for Amazon too.

I want to return the PSU as well but I don't know if its actually broken, and that I have evidence that it might be broken, so I don't want to waste a trio go in back to Manny again,

Finally, the ram sticks maybe broken, but I don't wanna pay anymore money to check it out. I've already spent too much. Besides, what really angers me is that I spent over £500 for the comp, hoping for it to be reliable. I've been told many times that buying from the shop is bad cos they compromise on the PSU and motherboard, this, that. Then mine breaks down within 6 months and its a massive pain to deal with. Its absolutely crippled my uni work etc. I just want it over with.

If any of you have an idea of what the problem could be, or at least have advice on my next course of action i'd appreciate it.

Thank you

Sorry for the long post.

 

[kajabla]

1. This is one of the more justified long posts I've seen. You've been through a lot with this thing.
2. Looks like the mobo to me—at least the mobo. Your experience is inconsistent with what you'd get for any one of the parts. It can't be the PSU, because yours works under some conditions and others don't work under some conditions. It's not the GPU, probably, because, again, cards aren't working or not working consistently. It's not the RAM, because, once more, a stick sometimes works and sometimes doesn't.
What ties together a bunch of weird, inconsistent behavior from all your parts? The motherboard.
Please check back when you get your new mobo in!