Computer Keeps freezing up

[forjonny]

his Pentium 4 2.5, 512, 40 + 80GB machine keeps freezing. Either on startup or as I get into Windows and start doing something.

I have switched out the ribbon cables, Unhooked floppy, other hard drive, CD drives and tried to get it to run and get the same thing.

I have switched out the ram.

I have tried to install Windows on the second drive because I thought it may have been a virus and it freezes 10 minutes into the installation. So it's not a bug.

I cleaned out all the dust with a compressor.

I reset the bios.

I am now taking out the battery and letting that sit for awhile.

I swapped out the video card.

The only thing that I have not done is swap out the keyboard and mouse thinking that those ports may be bad.

All capacitors look good. Flat on top that is. Some do have a slight curve on top of them but that may be the manufacturer making them with a slight curve on top. There are 9 of them with a very slight curve. Are some capacitors just like this? Some are real flat though.

I will try after the battery is out for awhile and then I will try again.

I will swap out the mouse and keyboard as well.

Don't know what else to try. Any ideas?

3 hours into this now.
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[Lgbpop]

Some do have a slight curve on top of them but that may be the manufacturer making them with a slight curve on top. There are 9 of them with a very slight curve.

That's a bad sign right there. The tops should be flat, almost concave in fact. Any bulging at all indicates failure - actual or imminent.

[Sterling_Aug]

Capacitors should NEVER have a slight curve on top.

If you can take a pencil erasure and push the ends back down, they may have liquid that squirts out.

Replace the mobo ASAP before it damages other parts in the system. I have seen a bad mobo destroy the hard drive on a system that had bad caps.

[forjonny]

To the untrained eye they do look flat. When you compare them to others they do have a slight curve upwards. They definately don't look round on top though or discolored at all. I will look at another computer to see the difference.

[forjonny]

This is what I discovered. The heatsink was impacted with dust. Couldn't even see the vanes under the fan. There are 9 capacitors right up next to the processor that have rounded tops. Any capacitors that are at least 1/2" away from the cpu are fine and flat on top.

Is it possible that the cpu got hot and cooked the capacitors that are right up against the cpu because these are the only ones that look this way?

[Sterling_Aug]

The capacitors next to the CPU are the ones that usually go bad on the systems that I have worked on.

Heat will not cook a capacitor. It was made using the wrong formula chemicals at the factory.

Replace the mobo now!

[BipolarBill]

...or replace the caps.

[Rocketmech]

...or replace the caps.

I agree , if the board will POST you have an excellent chance of repairing the board yourself by replacing the bad caps . Replacing an older board with a matching one can be very difficult or more expensive than a repair . If your not capable , then try a local pc or Video/Audio repair shop for an estimate .