Hello,

I am trying to fix a PC for a friend. The power supply had blown, so I have replaced that no problem. But the problem that was occurring before the PSU was that when you shut down the PC it all shuts down OK but the HDD light continues to flash until you completely remove power to the PC. And when I power the PC and try to boot up, the light will just flash and nothing else happens. I can't hear the disk spin or anything.
I am now assuming this is a hardware issue as I have managed to add the disk as a slave onto another machine and cleaned it up (there were no viruses).

Anyone any ideas?

Thanks in advance
ejw07

When power supplies go, they sometimes take other components with them. If you are not getting any POST beep on startup then the motherboard may have fried or the cpu or ram. First of all remove all other connections to the system other than power, cpu, video and ram. If this boots then add the other components one at a time until you find the faulty component.

If it doesn't boot with just these components connected, try clearing the CMOS (should be instructions in the motherboard manual) and try again. If this doesn't work, swap out any components that you can replace and try again.

Hi, thanks for your quick response! I removed everything apart from the essential. No response. I removed the momory, nothing. I tried a different hard drive and I still get the same problem. I tried the different ribbon cables, etc. The only thing that makes it beep is if there is no hard drive connected at all.
This suggests to me that it's the motherboard, yes?
I haven't reset the CMOS yet because I don't have manuals and haven't found out how yet. The PC is an Emachine 620.

Thanks, El

When the hard drive is removed, and the computer beeps, does anything come on the screen? Please remember that the hard drive is not essential for computer operation, it will work without one for testing purposes. We already know that the hard drive still works so you can leave this disconnected for now.

I agree that having tested with different hard drives and different cables, this tends to suggest the motherboard controller for the hard drive, but we can build the system up with everything else if it will work with the hard drive disconnected.

If it does turn out to be the hard drive controller, you can replace these with a PCI card either IDE (PATA) or SATA.

Hi, I went through the process again. The computer beeps when the hard drive AND the memory card is disconnected, and nothing appears on the screen. If I disconnect all the IDE cables from the motherboard and try to boot up, nothing, just the flashing light!
I connected everything back up and tried again and it booted up! But I couls not do anything because I didn't have a keyboard or mouse connected. So I went through the whole process again with the keyboard and mouse plugged in, but it wouldn't boot up. It would appear, from past exploration also, that the PC will boot on the odd, random, occasion. But there is no logic to why!

Look forward to your thoughts!

I have seen computers that would not boot simply because the mouse was not correctly plugged in (PS2). If the machine doesn't boot with mouse/keyboard removed again then it is likely that the failing component is randomly working. It can be very difficult to diagnose in these circumstances, all you can really do is start with the minimum that works, try it repeatedly and then build up the rest of the components slowly whilst repeatedly testing for startup errors.

I feel that this problem is probably the motherboard, if you can't find the motherboard manual to try the CMOS reset, look at the motherboard and find a small flat circular battery(about 2cm diameter), remove this for about 1 hour and replace, this should also reset the cmos.

Hi,
I have reset the CMOS, everything looked good on start up. It started up fine, asked me to check the time and date, and then booted up OK. Then I shut the PC down, and the same thing happened - the HDD light continued flashing! And now it won't boot up again!
Like you say, this seems to be very difficult to diagnose! I think I will return the PC to my friend and suggest the motherboard has failed and that they try and contact eMachines for advise!
Thanks again for all your help!
Elaine

Hi Elaine,

My wife's EMachines PC seems to have the same fault as you were describing. I wondered if you ever got the problem solved and if so what the cause was?

Alan

Hi Alan,

No, I never solved the problem. I put it down to a motherboard failure in the end. I do suggest you try all the suggestions above first though. It may be that you can use the disk as a 2nd drive to recover your data.

Good luck
Elaine