Anyone any good at diagnosing computer problems?

The old machine is refusing to start up. When you hit the power button, all the fans and lights and things turn on and it gets a variable distance through boot before it just freezes to a blank screen - and the monitor switches to "blinking LED" mode as if the computer's turned off. Sometimes it'll get as far as identifying all the drives and hardware and "Updating whateveritis pool data......Success" before it freezes, sometimes it barely has time to identify the video card. If it runs for long enough I can enter BIOS setup but it freezes after about the same length of time from startup.

I stripped out all the unnecessary components in the PCI slots and chucked in an ancient ATI video card and managed to get it as far as the Windows loading screen, but that's as much as it'll do.

Apart from swapping over the video card and taking out the expansion cards, I've tried removing the RAM chips one at a time and swapped them into different slots, and I've also tried a spare power supply unit - none of this made any difference with the exception that in a stripped-down configuration it starts up a little faster and so gets a little further into startup before it freezes. Oh, and I managed to slave the hard disk to another machine and copy data off it, so the hard disk is fine I think.

I'm suspecting the motherboard is slightly knackered, but I'm not entirely sure. Any suggestions would be very welcome. (It's an Athlon 800 on an Epox EP-8KTA motherboard running Windows 98 BTW).

 

Motherboard or power supply would seem to be the most likely remaining candidates. You've done a pretty comprehensive job in trying to eliminate everything else.

 

Thanks Isaac (especially for the speediness!) - I did try a PSU and got no joy. I guess the best bet now is to try to lay my hands on a motherboard of similar vintage from somewhere. Ho hum, Ebay here we come

 

Peter

if you can't find an old MB and need to upgrade, you could do worse than one of the upgrade kits on sale at www.komplett.co.uk they contain M/b Proc, ram and fan pretty good value.

P

 

I'm thinking memory dimms or CPU. Can you borrow these from anyone to try before a full m/b pull?

 

I had something like this happen to me a while ago and it was due to the CPU fan not working. I could hear the main fan for the box working but as the CPU fan (AMD)atop of the heatsink) was small and quite quiet the first I knew that it was not working was something like "CPU overheating" would flash on the screen for a fraction of a second before it all shutdown. So can you see the CPU fan working?

Auric

 

Maybe a good reason to have a window in the case then, all you naysayer, My case might be crass looking but LCD panel (for temps and fan speeds)and lighted window panel allow me to see if any thing is working or not.

 

You have pretty much done the things I would try, but there is one more: Many motherboards have a jumper that when closed enables you to completely flush the BIOS back to the factory defaults – it just wipes anything nasty that may have got in there, either a bad setting or a virus. This has worked for me a couple of times in the past with PCs that were failing to boot in the way that you describe.

Tony.

 

This sounds like it could be a CPU fan problem.
It would be worth taking the fan and heatsink out, making sure the interface between CPU -- heatsink -- fan is good, that the fan works and then reattaching the whole thing securely.
If it isn't a heatsink/fan problem, it may be a problem with the CPU or Mobo.

 

Thanks again everyone

I don't think the problem is heat related - I've just carried out three starts in quick succession and managed to get into the PC Health Check in the BIOS shortly before the machine stopped responding, and the temperature readings were normal all three times (the CPU fan speed seemed to be being read properly too). And the fan is certainly turning.

I've swapped round the memory sticks (there's one 64MB DIMM and one 128MB) and tried with only each one in turn, with no change - I can't believe they've both failed in the same way at the same time.

I'll ask around and see what bits I can borrow - does look like CPU or mobo at this stage AFAICT though.