# Dead motherboard or cpu??



## chezzam (Mar 8, 2007)

Hi

Had a couple of systems in last couple of weeks where either the motherboard or cpu has died and often come up against this same problem.

One system came to me 'dead'. Replaced motherboard & cpu and all is working fine now. The second system had intermittent lagging probs when running windows. Did all the usual things to fix the prob (did a Windows repair, defragged, cleaned up system and registry, ruled out virus/malware issues, etc etc) but finally determined that the probs were most likely hardware related. No warning beeps or anything else to help in diagnosis. Replaced the power supply and RAM but probs continued. Ran hardware diagnostics and stress tests etc (Hiren's Boot CD) but after 2 days, and before testing completed, the system died totally. I suspect the CPU may have been the problem but as testing was not completed can't be sure.

*My question is, is there any easy way to tell whether its the motherboard or the CPU that has died?* If I'm not sure, I generally replace both (which is what I did with both these systems). However I am finding I now have a few motherboard/cpu combos where most likely it is only one or the other component that has died, but I'm not keen to spend money unnecessarily. I'd like to be able to utilize the cpus/motherboards that are still OK instead of trashing the whole combo. Rather than going to the expense of buying a suitable cpu to test a motherboard, and vice-versa, I figure there's just got to be a way to test one or the other and figure out which one is dead! Is there??

Any thoughts would be appreciated.


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## Elunah (Mar 29, 2007)

Seems like a difficult problem to diagnose easily. Can you describe the "lagging" in more detail? What were you running when the lagging occurs?

As far as CPU vs. motherboard, if your CPU is dead, then the motherboard won't POST. However, if certain things are wrong with the motherboard, then it will cause the computer to cease to POST as well. The easiest way I can think of is to find another CPU that is compatible with your motherboard and to test your computer with that CPU installed. If it boots, then it was your CPU; if not, then it wasn't your CPU, though it might also not be your motherboard.

Did you get both systems from the same place? If so, might be time to find a new supplier


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## Compiler (Oct 11, 2006)

Yep... that why spare parts are handy for trouble shooting.

Keep a GOOD old-slow compatible CPU around. A dead CPU will always = dead PC. A malfunctiong mobo can be all kinds of problems.


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## chezzam (Mar 8, 2007)

Sorry its taken a while to post back. Been busy with other things.

Firstly, to answer the questions:



Elunah said:


> Seems like a difficult problem to diagnose easily. Can you describe the "lagging" in more detail? What were you running when the lagging occurs?


When I say 'lagging', I mean that it would suddenly run slowly - slow to open programs, slow to do a task, slow to respond to mouse, just basically SLOW! But intermittently - so sometimes it would run fine and then all of a sudden everything would be SLOW. It wouldn't matter what was running (at the time I did actually try to see if any software could possibly be the cause, but couldn't target anything) - all of a sudden it would just sometimes slow up in everything, then for no reason it would speed up again and everything would be fine. It was the sort of problem I have commonly seen with a faulty power supply.



Elunah said:


> Did you get both systems from the same place? If so, might be time to find a new supplier


Both systems came to me from different clients and were sourced from different suppliers. Both were btwn 2-3 yrs old.



Elunah said:


> if your CPU is dead, then the motherboard won't POST.........................If it boots, then it was your CPU; if not, then it wasn't your CPU, though it might also not be your motherboard.


When system 'died' I couldn't get a post or anything. Just dead. No motherboard lights, beeps or anything. So from what you're saying it sounds like the motherboard. As I'd eliminated power supply and RAM as being the issue, there's not really anything else it could be.



Compiler said:


> Yep... that why spare parts are handy for trouble shooting.....
> Keep a GOOD old-slow compatible CPU around.


I have so many different type motherboards come to me - from very old to new - that I'd need quite a few different "GOOD old-slow compatible CPU's". I work part-time from home as a tech tho so what you're saying makes sense. Guess I'll do some ebaying and see what I can find.

I recently found a great power supply tester for just a few $$ that's going to save hours of stuffing around. Can't believe in this age of technology that someone hasn't come up with a nifty motherboard/cpu tester that solves the problem once and for all!

Tnx for the advice anyway guys.


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