No longer POSTing / no VGA signal

[RhysAndrews]

Hi all,
I'm trying to fix my sisters machine, which has stopped POST-ing (no post beeps, no VGA signal, but everything powers up / fans spin). The machine is just older than a year old. My sister reports that it only did it once every now and again, and it's become more and more common. I booted it up once since I've look at it but haven't been able to since.

I think I've narrowed it down to either motherboard or PSU. If I remove the RAM, the motherboard beeps constantly. I tried replacing with other RAM that I have, and the same problem occurred (so it's not the RAM). I tried removing the CMOS battery for 15-20 minutes and then replacing it, no change.

The motherboard is a cheap MSI All-in-One, and the PSU is a generic (numan) 450 watter. I have no spares for either of them, so I can't test to see which one is causing the problem. What else can I try?

Thanks
Rhys

 

[foothead]

Try a different PSU or put the PSU in a different computer.

 

[RhysAndrews]

As mentioned, I have no spares. I can't take the power supply out of this machine as it's fairly well tied up with cable ties and I'd prefer not ruin it if I can help it... if I had a spare power supply I would connect it and test it (just not put it in the case), but I don't.

 

[foothead]

No chance you can pull one from a different computer?

Do you have a PSU tester?

Try jumping the green to black pins with a paperclip, then use a volt meter to check if the voltages are okay.

 

[RhysAndrews]

Afraid I don't have any tools like that.
I only have 2 machines I can put a PSU from, but one is very difficult to pull apart, and the other is my own machine which I'm not willing to use.

I was hoping there might be some test that would make it more obvious whether the motherboard was the problem.

 

[foothead]

not really.

You don't have a multimeter and a paperclip?

 

[RhysAndrews]

nope

 

[dude_56013]

My sister reports that it only did it once every now and again, and it's become more and more common.

Pretty common issue when PSUs start to die. I remember my old Dell. Would do the same thing. I would turn the monitor on and find the computer off (this was years ago before I even started my computer shop). If I banged on the PSU, I could usually get it to fire. Finally it just died altogether.

It could still be something else, so I still suggest you test this theory.

 

[RhysAndrews]

Thanks mate.
I've purchased a new PSU (I figured I could use it on my HTPC which has a loud, old generic PSU if it's not the problem) - connected it all up, turned it on... nothing.

Considering the motherboard beeps if memory is removed though, I don't think it's all dead. I just found someone who has a spare video card that I can try - just in case it's the onboard gfx. If not, I'll go ahead and get a new motherboard =[

Thanks guys,
Rhys