Dead Board? CPU? Grrr!

[MikeSamuel]

Just had a PC sent to me for some diagnosis and repair...Switch on, no beep, no display, but HDD seems to be working as if booting up. Tried with two different monitors, same problem. LED's on, and CD drive working etc...so PSU seems OK.. .Machine was working fine until moved from one premisis to another a while ago. I'm thinking maybe static damage or similar to the motherboard. Any ideas anyone else?

Cheers,

Mike

[ 20 February 2002: Message edited by: MikeSamuel ]</p>

[WhiteSail]

This is some information I had, and copied for you. Most is not of interest, but as the machine was moved, maybe the lose boards is significant.

Also, I had exactly that problem, and the keyboard and mouse PS/2 connectors were incorrectly marked. Changing these around solved the problem.

Beep CodeExplanation and possible solution

No BeepsSeveral things could cause. .your motherboard to remain silent: No power. Did you connect the power supply to the motherboard? Is the power cord plugged into the power supply and the wall? Is the input voltage selector set to the proper voltage for your area (110 or 220 volts). The motherboard isn't installed correctly in the case and it's shorting out. Check for proper installation. No speaker on the motherboard or no speaker plugged into the motherboard. A cable (floppy, hard drive, etc) plugged in backwards. Remember: Pin one on the cable is on the same side as the red stripe, pin one on the device is on the same side as the power connector on the device. Check all cables. An ISA, PCI, or AGP bus card not seated properly in a motherboard socket. Try reseated the cards. A bad clock generator on the motherboard (replace the motherboard).

Good Luck.

[shack]

I had exactly the same problem and it was the CPU not seating properly

[Superpilot]

You say the hardrive rolls as normal, if this is the case then the memory, CPU and m/b are fine. Sounds like either a duff graphics card or an incorrect setting for it within the BIOS (AGP/PCI settings). Normally, if this were the case you would hear a beep or two but I have been in a situation where there were no beeps.

Remove the graphics card and re-seat it. If still no joy read the motherboards manual and figure out how to reset CMOS (normally a simple jumper switch). Else I suggest you try out another graphics card on it. Any problems to do with the CPU or memory always result in a series of long beeps so I think its safe to assume those components are ok..........unless the internal speaker is disconnected <img src="wink.gif" border="0">

[ 21 February 2002: Message edited by: Superpilot ]</p>

[FL310]

Superpilot, there is a minor mistake in your assumption. The HD will start spinning even without any data cable connection, just plug the power cable in and start the machine up...

Mike, go as all others suggested, remove all and sundry, re-seat the CPU and than install step by step with start-ups inbetween.. .One more thing, remove also all RAM and while you have a bare motherboard, take a soft brush and clean it from any dust..... .Now check also (very important advice!!!!!!!!!!!!!!) the slots you put your cards in, you are not the first one who may have accidentally bent one of these tiny contacts thus producing a shortage. And, use a magnifier....

[Superpilot]

"but HDD seems to be working as if booting up"

I take that to mean as if the operating system is being loaded, i.e. the HD LED's are on. If thats not the case then sorry.

[abeesley]

I had a similar problem when I unpacked my PC after moving. It turned out that one of the pins in the SVGA monitor plug was bent. Straightened the pin, rebooted, Satis.

[MikeSamuel]

Cheers for your ideas guys, I think it may well be a graphics related problem, but as everything is onboard, it complicates things a little...Bloody Packard Bell :)

Regards,

MS

[boofhead]

What is the precaution about shorting out the mother board? Should it be earthed or insulated from the chassis? Or is it immaterial?

[allthatglitters]

Recently encountered a simular experiance. The computer was working perfectly well, it was moved and after setting up, the power supply fan was running with the hdd light on permenantly and appeared to be working, the cd-rom light flashing with nothing else, no beeps, no signal to the monitor, so suspected the monitor and tried another one, same as previous. The box was opened and the cpu had moved. One of those awful Slot1 Celerons with a large heat sink strapped to the back, which has to be restrained as the connecters are on one edge only.

[ 24 February 2002: Message edited by: All That Glitters ]</p>

[MikeSamuel]

Decided to actually do some work on this machine yesterday, had a good look around, and took the CPU out and replaced it - Worked perfectly after this, must have become slightly disloged during transit! Saved someone a hundred quid or so on a board and CPU!. .Quite amusing actually to come on today and read: . . [quote] One of those awful Slot1 Celerons with a large heat sink strapped to the back, which has to be restrained as the connecters are on one edge only. <hr></blockquote>

As this is exactly the type of processor that was on this machine. Must be a fairly common thing, so worth looking out for if you have the same problems. Thanks for all ideas and comments!

Regards,

Mike :)

[Belgique]

Also worth mentioning that I have twice found very recently that some very weird problems, one with a one-gig AMD Athlon and one with a PIII-750 were resolved by installing a new CMOS battery. I'm getting the distinct impression that these batteries are just not lasting as long as they used to. I can recall when CMOS batteries lasted four or more years. These carked it after about two. Maybe the battery-makers have reduced the capacity with the intent of selling more batteries (but instead just cause more motherboards to be trashed/replaced). Or maybe the motherboard-makers are getting smart and only installing inferior capacity batteries.

However, having bad-mouthed the M'board makers, only today my aged father was saying that his hearing aid batteries (also silver zinc) are lasting about half as long as they used to. As I usually get them for him, I can verify that. So is it all a plot? Planned obsolescence is a fact of modern life.