Mainboard needs replacing ?

[juliaatpcgp]

Hi,

My computer at work is playing up and I think its mainboard needs replacing but I'd like to be sure before I go and buy a new one.

The problem all started after we had a power cut at the office. My colleague's computer refused to power back again afterwards, so I replaced the power supply and it's now working perfectly again (and in fact I'm now using it as a loan PC because my own has broken !).

My own computer would power up for a few seconds and then lose power. This would happen each time you tried to power it up. So I replaced the power supply and seemed to cure the problem. But now my computer keeps restarting completely unexpectedly and each time it comes up with a message saying that the CMOS is bad and to reload settings but it fails to respond to the keys it tells me to press. I got it back the first time by turning the PC off for a few minutes then back on again. This time, however, it's not working.

Should I go and buy a replacement mainboard ?

Thanks for your help.

Regards,
Jay

 

[ArizonaGeek]

I'd say the motherboard is bad. At first I was thinking processor would be overheating if it is rebooting for no reason but if you are getting CMOS errors time to pick up a new board.

If you wanted to do some troubleshooting in the meantime, you could trying clearing the bios via jumper, check for a more recent BIOS and/or replace the CMOS battery on the board. Certainly cheaper than buying a new board. Just few things I can think of.

Cheers
Rob

The answer is always "PEBKAC!

 

[juliaatpcgp]

Hi Rob,

Thank you so much for replying so quickly and confirming my "gut reaction" that it's the board.

I'm glad you mentioned about processor overheating. Because I did get into the BIOS after I got the CMOS error the first time, turned it off for a few mins and then turned it back on. I noticed that although the CPU fan was running normally and the BIOS shows a revolution over over 3000 it showed the CPU temperature as about 75 degrees which struck me as incredibly hot.

Would a faulty board possibly explain the high CPU temperature even though the fan is still running normally ?

I can order a new board from my local supplier but I'd hate to get a new board and then find the CPU is faulty too and have to go and purchase one of those too, reducing the price gap between it being worth repairing or buying a replacement.

Any further advice you can give me would be really appreciated.

Regards,
Jay

 

[juliaatpcgp]

Hi Rob,

I forgot to ask whether you think the power cut (caused by a high voltage fault in the cables affecting over 2,000 customers in the area) was definitely, likely or unlikely to be the cause of my computer's problem ?

I would appreciate knowing because if I end up having to replace more than just a £30 part or even replace it, I will consider if I can claim against EDF Energy, our supplier.

Thanks.

Regards,
Jay

 

[jlockley]

Yes. Definitely possible. This not from a perspective of expertise but from experience. You have power strips?

 

[juliaatpcgp]

Thanks - I will ask EDF if they will consider a claim for this expenditure. Even if they agree, they could need an engineer's report confirming the board and/or CPU has been affected by the high voltage (more expense and delay in getting it repaired) or there may be so much red tape as to make it not worthwhile for less than 100 GBP expense but I feel I should try as it's their fault I've got all this hassle and expense !

The server is connected to an APC SmartUPS 1500 but the individual PCs and laptops, of which there are nearly 30 in the office. I did enquire some time ago about whether we should protect them and I was advised it was unnecessary in this country, only if you lived in an area with frequent thunderstorms.

What is your response to my observation about the temperature of the CPU even though the fan was still operating normally ? Does this make a board fault more likely to be the cause of my problems ?

Can you comment on the likelihood of replacing the board and then having to go back to the shop for a CPU to go on the board too ?

Thank you very much for all your advice.

Regards,
Jay

 

[juliaatpcgp]

Hiya,

After posting my original message, I did wonder if I shouldn't just see if I can replace the CMOS battery and see how the computer goes.

I got a colleague to help me remove the battery this morning and I had a spare CR2032 as I keep them for car/van remote controls. I fitted it.

Since then, the first time I started the PC and it died after a minute or so. Undeterred I decided to turn it on again and got a mesage saying the boot disk wasn't detected. Fortunately I'd seen this before on another PC and it was cured by simply connecting the disk to another lead coming from the power supply - it worked on this PC.

It's now booted up OK and is staying on for about an hour now and is fine. I do want to check the temperatures, though, so I'm going to list below the temperatures listed by a trial version of a temperature monitor I downloaded and I would appreciate knowing if they're OK.

C stands for Centigrade / F for Farenheight
CPU 29C / 85F
SYS 56C / 133F
AUX 25C / 77F
HD0 34C / 94F

Do you think I still need to consider replacing the mainboard if the PC stays on all day today without any problems ?

Regards,
Jay

 

[wahnula]

Hmmm...

Since then, the first time I started the PC and it died after a minute or so

Then...

it was cured by simply connecting the disk to another lead coming from the power supply

If this is not an indictment of a bad PSU I don't know what is! Just getting a PC working and stable by swapping PSU leads means that one rail or more is under or over voltage. This would explain the hot processor too. While it may be working fine now (meaning the MB is probably OK) PSU issues don't heal themselves and, now that you have diagnosed the problem, a new PSU should be installed ASAP before further damage is done.

Tony

 

[juliaatpcgp]

I don't understand - The original PSU was removed and replaced with a brand new one the first time the power died moments after starting up after the power cut.

As it happened with the new PSU, how could the brand new PSU be faulty ?

Since my last post, I've had the computer on test all day and it stays on all the time - no more losing power and no restarts or shutdowns, BUT the computer did freeze up once and the mouse would not move, so I had to press the Reset button. I've been told in the past that the mouse being stuck means a likely fault on the mainboard and with Si Soft Sandra saying the mainboard temperature was too high, I am sure it needs a new mainboard.

The replacement board is coming in tomorrow and I'll fit it over the weekend. Though I've built a PC from scratch, it was a while ago so I'm a bit nervous about this, but I'm sure I will be fine.

Regards,
Jay