Complete and utter failure

The computer we're working with currently is in a state of limbo. The power supply works fine, the motherboard and all components seem to run, but the only problem is that the video will not output. On occasions that it does output, the video will crash after about a minute or so. The northbridge fan is dead currently, but we have slapped on a heatsink with some Arctic Silver 5, and we're running a room fan with the open case. The video crashing symptoms typically happen before the system finishes checking the CPU and ram test. The video feed will either terminate or freeze at the current screen. Tests with an alternate working monitor rule out failure of the first monitor. Removed ram and tested in another computer, works fine. Video card works fine in other computer. Have not tested the hard drive, but we're assuming it works fine. Floppy drive is disconnected, we thought that it might have been preventing a good startup. Sound card hasn't been tested, but also assumed to be fine.

System Specs:

Intel P4 2.80 Ghz
Radeon 9800
SoundBlaster Audigy 2
Abit IS7 865pe motherboard
1 gig of Corsair XMS 3200 (cmxs12-3200c2pt)

Don't know what is wrong, could use a little help. Mods, move this topic if its in the wrong section.

Thanks.

EDIT:

Forgot to mention, sometimes on a semi-successful boot, the computer will say that the CPU has been modified, and needs to be checked. CPU is seated fine, and it should have no problems.

 

That in my experience means the mobo is kaput. The video goes through the northbridge and if it's fan died the chip melted in a milisecond like an overloaded fuse.

Moral: don't purchase mobos with northbridge fans! That turned out to be bad design. Abit is not good at replacing those mobos (with fans); had one that died only 6 mos. old and abit wouldn't honor the '3 year warranty'!

 

Sparrow is most likely correct but one thing makes me wonder. That is the fact that you sometimes get a partial boot with the video then freezing.

Have you tried clearing the CMOS?

If not, disconnect all power includeing the power plug to the main board. Hit the power button to discharge the capacitors. Pull the CMOS battery. Let it sit for a while. Put the battery back in. Hook up all power and give it a try.

Actually, while you have it apart you might also want to pull all the cards except video and ram.

You also said that you reseated the CPU. If you had to remove the heatsink to do so did you use thermal gel when putting it back on?

 

um, sorry if i was a little vague....i didn't actually reseat the CPU. the computer was complaining that we changed CPUs, when in fact we had not touched the CPU at all during this whole ordeal. i checked how well the CPU was on, to see if anything was loose, and it was seated fine.

 

The graphics work...up to a point

I might wonder about the CPU overheating. Can you see any dust in the CPU heatsink fins? If so, you can unscrew the CPU fan and clean the dust out the heatsink.

May well be the northbridge chip is somewhat "cooked ", but I would expect that you would not get any graphics at all.
I went into my local computer store the other day and was surprised to see a full range of northbridge heatsink/fans when he does usually carries only minimal hardware stock. Looks like you are not aloan.

Suspecting an overheated CPU, it might pay to remove the CPU heatsink and replace the thermal compound. You probably know, a detailed tutorial is at the Arctic Silver website.

Matt

 

Graphics work up to a point, but machine won't boot and gives a spurious message. Mine said BIOS was damaged. Graphics card worked in another machine for a month or so and finally lost its resolution above 16 bits. Was RMA'd and replaced without any problem with a new card. Partial northbridge damage is enough to kill the mobo. See this definition

 

Even though I fully admit that Sparow most likely knows more than I do in most aspects includeing this, I would still reset the bios before scrapping anything.

 

Sparrow, thanks for the extra info, those things are good to know.

Sometimes the graphics start, sometimes not. I find that if hardware is bad it will do the same thing every time. If there is a heat problem though, it will do different things ocassionally.
I would still investigate getting the cooling settled down. Even if unsuccessful it would be a learning experience for me.

Matt
PS Please consider my spelling mistake (alone) corrected (too late). It should be common knowledge that hardware people are EXEMPT from spelling mistakes