PC Dead - Advice on Determining the Fault

nheather

nheather

nheather

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Horsham, West Sussex
Hi,

Last night when I went to switch off my PC I found that it had frozen. Full screen display but couldn't move the mouse etc.

Didn't think anything of it - just hard powered off and went to bed.

This morning - the power supply starts up with a touch of the soft power button - but no BIOS screen. Also note that the I can't reset or power off using the font panel buttons - have to use the PSU switch on the back.

There is no POST because my case does not have a speaker - looking at finding one to wire up.

Tried swapping in an old graphics card but still no joy.

MOBO is gigabyte GA-MA790FXT-UD5P

Annoyingly threw the box out only a couple of months ago and can't find the manual in the safe and tidy place I must have put it. Tried the gigabyte site but that only has the quick install guide, not the full manual.

PSU is Corsair TX650W.

Thinking that as there is no life other than the fans spinning then it is either the PSU or MOBO. Is that right? And any idea how I could tell which one?

Cheers,

Nigel
 
I have opened up my son's PC and connected it's PSU to my PC.

I've left his PSU in place but connected its two MoBo connectors - the big one and the 8 pin one (made up of two 4 pin) to my MOBO and the PCI to my graphics card.

Same result - fans spin up but no sign of life from the MOBO - no BIOS splash screen etc.

I think that has eliminated my PSU as the problem - am I correct.

I'm now thinking my MOBO is dead - assuming that if it were RAM or CPU then it would at least show some sign of life in the BIOS - is that correct?

Cheers,

Nigel
 
Unfortunately you have no speaker so you can't tell. It could be the RAM, the CPU, or something else. The beep codes would tell you. And no, you wouldn't necessarily see anything on screen.

Have you checked the motherboard for blown capacitors or resistors? Stray screws that might have caused a short circuit?

The manual is available if you search for it on Google.
 
Yes found the manual now - just not on the gigabyte site.

Have tried resetting the BIOS, also removed BIOS battery and checked its voltage - that is all good.

So I need to get a speaker onto the MOBO. Frustrating is that over christmas had a tidy up that included taking to old PCs to the tip - they would have had a speaker I could use.

You can buy them on eBay but I really wanted something today.

But some further questions - if it were RAM wouldn't it still get to the BIoS splash screen.

The MOBO seams totally unresponsive. For example before switched on the MOBO is lit (it has onboard buttons for power and reset).

If I hit the power button, either case front panel or onbaod then the fans start spinning. But if I then hit reset, either on the front panel or onboard nothing happens.

Cheers,

Nigel
 
It'll be a pain, but take the motherboard out the case and sit it on plain cardboard for testing.

Other things to try are reseating your RAM and making sure your CPU heatsink isn't on too firmly. In fact, maybe even try reseating the CPU and check to see how evenly spread the heatsink compound is on the CPU - if it's at one side, it might be sign of an over tightened heatsink.
 
darael said:
It'll be a pain, but take the motherboard out the case and sit it on plain cardboard for testing.

Other things to try are reseating your RAM and making sure your CPU heatsink isn't on too firmly. In fact, maybe even try reseating the CPU and check to see how evenly spread the heatsink compound is on the CPU - if it's at one side, it might be sign of an over tightened heatsink.
Click to expand...

Thanks will try the RAM.

Don't think the heatsink is too tight - the computer has been running fine for five years or more. I guess the thermal compound could be drying up and need replacing but again I would have thought the symptoms of that would that it would boot up and then crash later as it heats up.

Cheers,

Nigel
 
Looks like a mobo/PSU/RAM/GPU issue, CPU error is very rare.

As suggested take the mobo out and try to power it with just 1 stick of RAM with no HDD in and just a keyboard/mouse plugged in (may not even those).

Do you have any old parts like GPU/PSU/RAM for a swap test?

Also the manual was on the gigabyte site at the bottom of the page. :D
 
Sasahara said:
Looks like a mobo/PSU/RAM/GPU issue, CPU error is very rare.

As suggested take the mobo out and try to power it with just 1 stick of RAM with no HDD in and just a keyboard/mouse plugged in (may not even those).

Do you have any old parts like GPU/PSU/RAM for a swap test?

Also the manual was on the gigabyte site at the bottom of the page. :D
Click to expand...

Hi,

This is what I have tried so far

Different GFX card - no difference
Different PSU - no difference
Different RAM - no difference

When I tried the different PSU, only the MOBO and GFX powered - so that has eliminated drives etc.

Just off to Maplin as they have a testing kit that allows you to run a MOBO on the bench without the case - so includes a plug in buzzer. Will be able to tell whether I'm getting any POST beeps then.

Failing that will reseat the CPU heatsink.

Can't tell whether the capacitors are bad - it is advertised as having ultra-durable Japanese solid capacitors so you don't get the tell-tale signs that you do with electrolytics.

Cheers,

Nigel
 
Hi,

Just got back from Maplin and plugged the the speaker/buzzer into the motherboard.

Not a sound at all.

Sort of goes hand in hand with motherboard not responding to the power switch to turn off or the reset switch.

Looks like the motherboard is completely dead - not starting up at all so no POST beeps.

What do you think - dead motherboard.

Next step (but that will have to be tomorrow now) is to take the motherboard out and try powering it up on the bench - but suspect it is a new motherboard.

Question - my CPU is an AM3 - the new boards are AM3+. Am I correct that the AM3+ boards will accept AM3 processors? Is the heatsink fitting the same?



Many thanks,

Nigel
 
Ignore what I said about the heatsink and CPU - I automatically assumed you had an LGA processor which uses pads instead of pins to make contact with the motherboard. :o

It does indeed sound like the motherboard. Are there any signs of bulging capacitors, even slightly?
 
darael said:
Ignore what I said about the heatsink and CPU - I automatically assumed you had an LGA processor which uses pads instead of pins to make contact with the motherboard. :o

It does indeed sound like the motherboard. Are there any signs of bulging capacitors, even slightly?
Click to expand...

Hi,

This morning, I have removed the MOBO, and connected the PSU (a third one), and the speaker.

Start it up and no beeps at all.

A guide I was reading said that if all were well I should get beeps at this point complaining about the absence of memory.

However, it does also say that if I get no beeps then it is a PSU problem. I find that hard to beleive as I have now tried three different PSUs.

I imagine that if the MOBO were completely dead then it would not start up so would not be able to give beeps, even with a good PSU.

No sign of bulging caps but the are not the traditional huge electrolytic cans but tiny little things - the advertising blurb says that they are ultra durable japanese solid capacitors.

But just before I press the 'order now' button for a new MOBO is there anything else I should try. The only other thing I could think is a dead CPU but that sounds like it is very rare and I have no means of testing it anyway.

Cheers,

Nigel
 
Quartz said:
Before you order a new AMD motherboard, consider if you want to switch to Intel.
Click to expand...

This is just my office computer for browsing, mail, MS Office, and a few games like World of Tanks etc.

I have an Intel based gaming machine in my man-cave.

More than happy with it so just looking to get it back up running.

Cheers,

Nigel
 
Just had a day of slogging with a faulty computer. It would start, fans spinning, but no BIOS display or anything, and no signs of keyboard life. The cause ended up being the tiniest speck of dust/dirt on one of the hundreds of tiny gold contacts on the CPU. Cleaned it with TIM Purifier, dried it, and it sprang to life. FWIW, something to try.
 
If you upgraded to AM3+, then you'd be able to utilize the existing RAM/CPU (assuming they still work).

There are Asus AM3+ boards that have a in-built POST LED display to check error codes instead of having to use a speaker.
 
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