What could go wrong without video signal?

[cpliu]

I'm having problems with ASUS P4B266c with P4 1.6GB CPU. Initially, it
always freezed at 2/3 of way to Windows 2000. It booted with safe mode, it
stopped at mup.sys. I disabled it with System disk. It only worked a few
times afterwards, the same problem came back. I could still boot to Windows
XP, but I need Windows 2000. I reinstalled the system and it worked again
for 1 or 2 times. The same symton came back again. It got worse and worse
after that. I took all the card out except video card. I took the memory
out and switched location. I could boot one more time with one memory (DDR
256MB). Then, the system didn't even give BIOS screen. Then, the system
didn't output video signal. I am sure my video card works since I could use
it on another system and my monitor is fine too. One time, it gave out a
bi-ba bi-ba noise when I booted. I switched battery and the noise went
away.

What is wrong with my PC? CPU? mainboard? power supply? I don't know where
else could be the problem.

Thanks for any suggestions,


cpliu

 

[Peter Wilkes]

Hi,

Just to rule a few things out...

This is not a software problem. The bleeping noise that is coming from your
motherboard is trying to tell you something is wrong. Could be processor
overheating, over or under voltage etc. Problems with specific components
e.g. ram, graphics card often do a single bleep code.

If possible I would try again when the system has cooled down. If it is
still beeping or beeps when you boot up take the case off and check the fans
are still running and feel the temp of the heatsink (it my be hot) It should
be quite warm but not too hot to touch.

Try these things and let us all know if you manage to find anything.

PW

 

[Ben Pope]

I'm having problems with ASUS P4B266c with P4 1.6GB CPU. Initially, it
always freezed at 2/3 of way to Windows 2000. It booted with safe mode, it
stopped at mup.sys. I disabled it with System disk. It only worked a few
times afterwards, the same problem came back. I could still boot to
Windows XP, but I need Windows 2000. I reinstalled the system and it
worked again for 1 or 2 times. The same symton came back again. It got
worse and worse after that. I took all the card out except video card. I
took the memory out and switched location. I could boot one more time
with one memory (DDR 256MB). Then, the system didn't even give BIOS
screen. Then, the system didn't output video signal. I am sure my video
card works since I could use it on another system and my monitor is fine
too. One time, it gave out a bi-ba bi-ba noise when I booted. I switched
battery and the noise went away.

I would suggest failing power supply, it's the only thing that tends to go
slowly like that, and could cause all of those symptoms.

If you can get into the BIOS, check the voltages. +12V and +5V should be
±10%, +3.3V should be ±5%. My suspicion is that the 12V (and therefore the
+5V) will be sagging. Ignore the negative voltages, they're not used, but
should not be low (towards 0V) as they're unloaded.

If you've installed new hardware that could be why you're now experiencing
it, but they can just die in normal use.

Ben