Troubleshooting A Almost Dead Pc, Out Of Ideas.

[glowstar]

I bought a pc for £10 as it didn't work, all I really wanted was the case, but when I got it I saw it was a Acer Aspire T650 with a Pentium D 820, 1GB DDR2 and a PCI-E gfx card so I thought it may be worth getting running to use as a HTPC.

The problem:

When I pressed the power button the PSU and CPU fans spin up, but nothing comes on screen, no beeps.

What I've tried so far:

• Tried both VGA and DVI on the PCI-E gfx card, and the on-board VGA.
• Tested PCI-E gfx card in another machine, works fine.
• Tried with and without hard drive connected.
• PSU tested and works fine, tried another PSU too.
• Took RAM out to see if speaker works, powered up and it beeped continuously until powered off.
• Tested RAM in another PC, works fine.
• Reset CMOS on motherboard.
• Tried the CPU in two other socket LGA 775 motherboards.
• Tried a Celeron D CPU in the three different motherboards.

Through all that, the only thing that would happen is the PSU and CPU fans spin up, but nothing comes on screen, I'm out of ideas as to what could be wrong.

I would really like to get this box working, seems a shame to let it go.

Edited September 9, 2010 by glowstar

[Sparda]

Seems like the motherboard is broken.

Have you tried disconnecting every thing (USB ports and similar).

[Mr-Protocol]

Does it have an onboard graphics card?

It probably isnt setup in BIOS to use the PCIe card and is spitting all the video out of the onboard card.

My old desktop, the BIOS wouldn't let me disable the onboard. So the splash screen of startup would be on the onboard video, and it would show nothing on the PCI video card until Windows was booted and Windows told it to use that card instead.

[iisjman07]

Here's what I would do:

1) Remove the RAM from the machine, see if you can get the BIOS speaker to go off

2) Try a known good power supply

3) Reset the BIOS using the reset jumpers

[glowstar]

As I mentioned, I've tried three motherboards...

Sparda, all that was connected was the power switch.

Mr-Protocol, Only one of the three motherboards has on-board and I tried that too (with and without the PCI-E card connected).

iisjman07, I have tried all that on all three motherboards.

[Mr-Protocol]

Salvage all usable parts.

Go outside with motherboard.

Use USB Crowbar to Brute force it -OR- Shotgun...

Enjoy Victory.

[VaKo]

So basically its this combination of parts that doesn't work together, but the parts all appear to work independently in other systems? Have you tried removing the case from the equation?

[glowstar]

Yea, tried them all out of the case on a desk, only the one that came with the case has been in the case.

Going to borrow a motherboard tester that you stick in a PCI slot soon, so maybe that will yield some further results.

[digip]

Dumb question, but the monitor you are testing with, is it known to be good? Does it work on another working system. Just wondering if its working and you just cant see whats on screen because of the monitor itself.

[glowstar]

Not dumb question, I didn't state if it worked or not. But yes, it does work with other PC's I have, so it's not the monitor that's not working though I wish it was :/

[Infiltrator]

Here is what I would do.

1. Test the memory on another system to see if that works

2. Test the CPU on another system to see if that works

3. Test the power supply of this system on another working system

4. Unplug all the cables and make sure the PSU is only supplying power to the motherboard and the HDD, then try turning on the computer.

5. If the motherboard has internal graphics card, try installing an add on one to see if that works

6. If all the above fails, buy another motherboard.

Regards,

Infiltrator

[glowstar]

Update, I have a motherboard tester now. I stuck it in and it gave the code A1, which according to the booklet means "Check key lock", and as I mentioned its a Acer Aspire T650 with a Pentium D 820, 1GB DDR2 and a PCI-E gfx card, there are no key locks or case locks etc in sight.

I have no idea where to go from here, I have no idea where the "key lock" is and how to check it... any advice appreciated.

[BattZ]

What tester are you using for that? and have you tried another monitor? I have an extra monitor that's pretty flaky, you have to make sure it's on the right setting, right input, if it's plugged into the machine too late it won't work, just strange things like that.

Has all these tests been with HD's connected? or no?

And I thought I read you tried plugging everything into another motherboard, and it still doesn't work, but I can't find it so I'll just double check that.

BTW, those things, I think they're crepes in your little avatar thing, look delicious.

[digip]

Update, I have a motherboard tester now. I stuck it in and it gave the code A1, which according to the booklet means "Check key lock", and as I mentioned its a Acer Aspire T650 with a Pentium D 820, 1GB DDR2 and a PCI-E gfx card, there are no key locks or case locks etc in sight.

I have no idea where to go from here, I have no idea where the "key lock" is and how to check it... any advice appreciated.

Do a find in the page on "keylock":

http://www.pcguide.com/proc/config/mbcase-c.html

edit: Maybe something is on the keylock jumper that should not be, or you can somehow bypass it. Might have to google for the MOBO's install booklet and see what the settings are for the jumpers/pins

Edited October 3, 2010 by digip

[enlight22]

i guess north bridge failure, most likely due to bad BGA joints.

[mike.lindsay]

Yea, tried them all out of the case on a desk, only the one that came with the case has been in the case.

Going to borrow a motherboard tester that you stick in a PCI slot soon, so maybe that will yield some further results.

I don't know if your response to that means you have taken it out of case or have just tested all the other ones outside of the case. Anyways if you haven't then try to remove it from the case and make sure there's no screws or anything grounding it anywhere.