motherboard problem?

[sjthebat]

Hi, I need help here!

My computer is up and running for two years. I have a really strange problem now.

The monitor cannot detect any input signal when I boot my machine. When I turn on the power of my machine, it seems that it is doing its booting stuff. (I can't really tell because no display on monitor) I've tested the monitor using a laptop, it works fine. Next, I tested my video card on another machine, it works fine.

So does that mean my motherboard has some problem? Or anyone has any idea on what may cause this symptom?

Many thanks!

Jian

[Budfred]

Welcome to http://www.pcguide.com/ubb/pcgubb.gif

It probably doesn't mean that your motherboard is bad since everything seems to be working except this. I would make sure the video card is properly seated, make sure the video cable is properly connected and, if possible, try a different monitor on the computer with the same video card. This will help to narrow the possible causes. Let us know how it goes and we can try to help from there.

Also, tell us more about your computer and particularly the video card and monitor.

[sjthebat]

Thank you very much for your reply!

It's a Pentium III 600 machine with Abit BE6-II motherboard. Video card is 3dfx Voodoo 3 and monitor is ViewSonic A70.

Since I have access to an older machine (Pentium-MMX 233) that has no problem, I did several experiments this afternoon:
1) I plug the monitor of the old machine to my current box. I got the same symptom. No display on the monitor.
2) I swap my Voodoo card with the old machine's Matrox card. Then, the old machine with my Voodoo card works fine. And my box with Matrox card gave no signal to the monitor.
It seems to me that the culprit is the motherboard. But before replacing the motherboard, I really want to do more probing and tests.

[Budfred]

Are those AGP or PCI cards? If they are PCI, try them in a different slot to see if you get video. If they are AGP, see if you can borrow or buy a PCI card to see if you get video. It is more likely a problem of seating in the slot or the slot itself than that the motherboard has gone bad if everything else is working.

[Fruss Tray Ted]

it seems that it is doing its booting stuff. (I can't really tell because no display on monitor) Do you hear any beeps? Are the fans spinning up? Have you tried to get into BIOS? Any display there?

Just trying to eliminate the possibility of it's being the power supply. You might want to do a barebones boot also. Disconnect all optical drives, harddrive, CDROMs and floppy. Then try to boot or go into BIOS.

Also check all power connections. Unplug and reinsert them to refresh the connection, always powered down of course.

[sjthebat]

Originally posted by Budfred
Are those AGP or PCI cards?
It's a PCI card, and I did try it on another slot. Still no monitor display.

Originally posted by Fruss Tray Ted
Do you hear any beeps? Are the fans spinning up? Have you tried to get into BIOS? Any display there?
No beeps. And the fans are spinning. Maybe I will try to remove and re-insert everything and do a barebones boot. [But I am overwhelmed by homework, so do not have much time to work on it.]