Troubleshooting a CPU

[Lucatov]

I have just built a new computer.
I had trouble with an intermittent contact power supply (ATX) cable.
For a few hours I was able to work with it just by jiggling the wires.
At some point while this still remained true, the monitor stopped working.
The power led on it no longer changes from flashing yellow to green when I turn the PC on.
It still works correctly with my old PC.
I have replaced the MB with no result. Now I am thinking CPU.
The power supply seems to be working (PC turns on, hard drive powers up),
but the monitor still remains dark with flashing yellow led.
Can you advise on anyway I can determine whether the CPU is the problem
short of trying it on another PC I don't have access to.
My old PC is a Pentium 133Mhz, the new one has Abit BH6 MB, Celeron 400 CPU.
Thanks for whatever help you can provide.

Luca Tovini
gtovini@earthlink.net

[Bleeding Edge]

This is a computer that is up and running that has a fresh copy of an Win95/98 on it?

It sounds like your computer and monitor are going to sleep. To remedy this go to ControlPanel/PowerManagement and select "never" for the monitor and hard disk.

Reboot the system.
Go directly into the Bios setup and disable the power saving features of the motherboard. Then reboot to the OS.

[Lucatov]

Yes I do have operating system installed (win98).
Unfortunately with a dark monitor I can't go anywhere not even to bios setup.
There is no beep either doesn't that mean the PC is not posting?
That is why I am thinking CPU or memory.
They were both working before though.
I have since also tried the memory in a different slot and disconnecting the hard drive.

[Bleeding Edge]

Have you reseated the video card to double check that it is pushed down all the way.

Are you able to try a different video card.

Have you double checked all the jumper settings for the CPU and memory.

It is doubtful that the CPU is bad, however, people have been having memory related problems with this board. Whether do to the fact they are buying the bad/wrong type of memory or miss matching the CPU/Memory bus frequency or just getting the jumper settings wrong, I don't know.

You said you jiggled the wires and it helped for a bit, right? Was this the power supply connection to the motherboard? I've seen those pins encased in the plastic housing of the connector actually get pushed up because they weren't assembled right. Therefore loosing contact.

The monitor works okay with the other computer?

[Lucatov]

Tried other video card: no change

No jumpers on this MB except for CMOS reset: I have tried resetting that.

Power connector to MB looks OK although I can still make and break the contact by moving the wires. It is working however because all fans work and the drives spin.
Memory is Micron-8 128 MB SDRAM CAS2.

Bleeding Edge, I appreciate your efforts.

[Bleeding Edge]

I should learn my lesson here.

I really haven't been able to successfully help those who own the BH6.

That particular board always takes me for a loop.

Hmm..

If you haven't found a solution as this day grows latter, I hope someone here will.

[Myke]

Here is my take on this.
The ps applies different voltages to different parts of the system.
Because the drives and the fan are working,dosen't mean the proper voltages are getting to the cpu.

The fact that you can make or break contact by jiggling wires, suggest that you have a broken wire which will cause impedance problems to whatever component it's feeding.

If we now assume that the ps is working fine, then you are absolutely right, you are not passing post hence no video.

Oh oh my part just arrived, I'm a service technician. Have to get back to work. will continue this later.

[MaxVal]

This problem typicaly results from:
1-Bad contact on video card, bad card (unlikly}. Remove and reseat.
2- Bad contact on memory dimm, or bad dimm. Remove and reinstall. Try different slot, try a different dimm.
3- Make sure CMOS settings are correct. Restore all setup defaults.
4- CPU- Check in a working system.
5- M.B.- Bad contact somewhere or just bad M.B.
I,m sure there are many other possibilities, but these are the most common.
Good luck!!

[Lucatov]

Tested the CPU on a PC at work: same behavior.
I am not happy, but the puzzle is solved. I will get the CPU replaced.
Thank you all for yor ideas and support.

[Bleeding Edge]

It rarely happens. The chip must have been mishandled. Because if it was during fabrication, the entire lot of CPUs would have the exact defect.