is the CPU dead?

[Corbit]

Hey there!

Yesterday morning my computer simply wouldn't start up. I'm now trying to figure out what's wrong, and I hope you could give me a hand.

When I hit the power button the fans starts running at a high pase, but nothing else happens. The screen doesn't have a signal and the keyboard isn't recognized. I tired to switch out the motherboard, and nothing changed.

Personally I think it's the cpu, but I need some feedback on the thought.

Thanks

[Rondog]

Dead motherboard without a doubt.

[Áedán]

Whenever you're trying to work out if it's the CPU or motherboard, you ideally want as little in the system as possible.

The system should be able to get itself running with a PSU, a CPU, a motherboard and some RAM. Nothing else is required - no keyboard, no mouse, no video card, no hard disks. You will need a speaker connected to the system though - as it should beep at you to say there's no video card.

If you tested with a different motherboard, but had all the cards etc installed, then it's not necessarily a good test. For example, a dead graphics card can cause the same symptoms as you're seeing at the moment.

Also useful is another power supply, or some way to check that the PSU you currently have is working properly. Given that the fans work, it suggests that the 12V line works ok though.

[Rondog]

BTW: Welcome to AOA!

[Corbit]

Originally Posted by Rondog

Dead motherboard without a doubt.

Tried with a different motherboard which changed nothing, so it's doubful.

[Corbit]

Originally Posted by Áedán

The system should be able to get itself running with a PSU, a CPU, a motherboard and some RAM. Nothing else is required - no keyboard, no mouse, no video card, no hard disks. You will need a speaker connected to the system though - as it should beep at you to say there's no video card.

If you tested with a different motherboard, but had all the cards etc installed, then it's not necessarily a good test. For example, a dead graphics card can cause the same symptoms as you're seeing at the moment.

I've tried running it with motherboard, ram and speakers - I did not receieve any sound from neither missing video card nor missing keyboard, the fans just kept running in the same pase.

As said above I doubt it's the motherboard as I've changed it, so is there a way to test if it's the CPU before I buy a new?

[Gizmo]

Any modern motherboard should give you a series of beeps if you don't have any RAM installed. In other words, the bare minimum to get the system up and running is the mobo, PSU, and CPU.

Whenever I have a question about a piece of hardware I'm working on, the first thing I do is pull the mobo and PSU out of the case and set them on my (wood) workbench. (Don't want any conductive surfaces.)

The only thing you want attached to the mobo is the PSU, CPU, and speaker. Not even the case controls (I've seen a couple of times where a stuck reset or power switch caused some weird problems). You can use a wire to jumper the power-on switch.

If the thing doesn't power up at that point, you've only got three possibilities because you've only got 3 components. If you swap the PSU and the behavior doesn't change, then its probably not the PSU, etc., etc. Rinse and repeat with the other components until you've narrowed down what it CANNOT be. Whatever's left must be where the problem lies.

[Daniel ~]

Welcome to AOA Corbit!
Have you tried pulling the plug and battery on the Suspect Mother board? Wait a few then retry?

If you haven't tested with JUST CPU, PSU and Motherboard...you really can't be sure yet

[Rondog]

Well I'll eat my hat. Hmmm, unless two components have failed. To my knowledge, a board wont beep for a CPU fail, someone else can confirm.

Borrow a CPU from a friend is all I can suggest.

[Gizmo]

Seeing as how the speaker beep is controlled by the CPU writing to an I/O port, no, you won't get a beep unless the CPU is coming up.

There ARE a few exceptions to this. Abit's μ-Guru is one; it is an independent microcontroller that monitors system operations and is capable of sounding the speaker if it detects that the main CPU is non-functional. However, those types of systems will also tend to have on-board diagnostic leds to indicate particular system problems, and there will be a list of the codes included in the manual.

[Corbit]

Thanks for your replies and help - I've come to the conclussion that I need a new CPU, so I'm gonna try and raise some money for it.

[Samuknow]

Welcome. What CPU did you loose?

[Corbit]

Originally Posted by Samuknow

Welcome. What CPU did you loose?

a QX9770 @ 3.2, which has been cooled properly at all times, and I haven't even seen it fit to oc it yet.

What I can afford now is something like a 2.0ghz dual, so it kinda sucks you know.

[MUff1N]

In General CPU's are very hard to kill if they are already working. One member had a Q6600 running at 1.8v when the voltage regulators went bad & it didn't die!
The only way that CPU would die is if for some reason the voltage regulators went bad on your mobo & fed it way too much voltage...

There's no way it would go bad at stock speeds if it was already working unless the CPU got to much voltage.
(This is a very good reason to always monitor your Core Temps with Core Temp!)

There are good CPU's & bad CPU's.
They either work or they don't.
As far as OCing potential that's another story but since you weren't that's not even in the picture...

I wouldn't be so quick to throw that QX9770 away & check it out on a working mobo first...
OR, take it to a shop to have it benchtested. (this is what I would do)
Should only cost a few bucks for their time & well worth knowing for sure at the price of that processor!!!
The PC shop here in our town (pop 14,000) will bench HW parts for free!

I've got a feeling (a hunch) this isn't your QX9770 at all, but another HW component(s) in your system that's gone bad.
Btw, I've been right more than wrong on my hunches...

Anyone else have a thought on this...

[booman]

Don't forget to note "speaker" as the computer speaker that plugs into the motherboard. Some are actually attached to the motherboard.
I just don't want anyone to think plugging in their desktop speakers are the same thing. You know, the speakers you listen to music through and plug into the green speaker out on the back panel.

[booman]

Also, I agree with the CPU not being the problem. I've never overclocked any of my processors and I have never burnt one out. If it worked on the first day, it is still working now. The only thing that can burn them out is not properly using thermal paste with the heatsink and it overheats. Usually the motherboard BIOS is set to shutdown before it goes into meltdown.
I would take it to a shop that can test it before you trash it.
CPU's are like gold to us....