Lost Video

[Ray2047]

On my main computer I have been loosing video to the monitor at random during boot. I thought maybe a bad video card but until day before yesterday rock solid after it finally booted. Then it started loosing video signal after booting. Finally gave up all together. Checked monitor and no problem. Figured it was the video card. Pulled the video card and plugged the monitor in to the on-board video. Worked for a very short time then failed the same way.

I'm thinking memory but it is only a guess and can't check. The computer does boot but no video signal to the monitor. Can't run a memory check because no video. Any guesses welcome. Hate to buy new memory and that not be it.

[ElCuervo]

Have you tried  memtest  from the LiveCD on boot?

[Ray2047]

Have you tried  memtest  from the LiveCD on boot?

I have no video. How could I do that? Am I missing something?

[Xenaflux]

The computer does boot but no video signal to the monitor

I am not trying to be funny, but if you have no video signal, how do you know it's booting up ?
I have exactly the same problem on an older computer.
Press the button....computer seems to boot...no screen

I also don't know for sure what it is, but if I , during one of those so-called  boots, just switch off, and try again 1 or 2 times times, it boots properly

Culprits:
on-off switch ?
Power supply ?
Wiring ?
something on the motherboard ?

Wish you good luck with yours
For me, I just keep patiently pressing the button  
Xena

Note: On my comp, I always have a little beep when they switch on.
When I hear that beep, on the exact moment, my monitor switches on.
No beep, no video

[Ray2047]

I am not trying to be funny, but if you have no video signal, how do you know it's booting up ?
I have exactly the same problem on an older computer.

Indication one is the hard drive activity light. Number two is when I first started having this problem after two or three tries when I finally got video during boot I got the "improper shutdown" message indicating that the computer had probably been running when I hit the reset button. Yep, normal beep activity.

[Xenaflux]

Indication one is the hard drive activity light.

As far as I remember, my HD light was also flickering on an improper boot up.
I just tried that computer, and of course, now he  boots up properly every time I tried ( 5x )

.....indicating that the computer had probably been running

Running, yes....but properly or improperly  ?   ?

What about trying a LiveCD
1-- pclinuxos liveCD
2 - Knoppix LiveCD
3 - Gparted or Parted magic live CD

My experience is that all three behave slightly different ( no clue as to why )

Maybe you may draw a conclusion about something ?

Xena

[Ray2047]

Thanks Xena. Don't disagree. Will try the live CD tomorrow.

[Ray2047]

Update: No, same problem with live CD. I am beginning to lean toward the main board but just guess. I'm thinking something on the main board that handles the video.

[ElCuervo]

Can you even get into the BIOS?

It sounds like you do have hardware problem.

[Xenaflux]

Have you tried to re-seat your memory sticks....unlikely,  but.....
Take out the CPU chip if that is possible and just put it back....?

Bad contacts can develop over time.

Just for your amusement 
I have another 10 year old computer.
It started the same...bad boots and only half the memory
I located that the memory was bad
After numerous times re-seating it, finally it was OK....for a few months
Then it started again
I took every thing apart....to no avail.
Finally I took it to a friends shop
He had it for a few months, checked every thing separately and all was well.
Put it together again...same story...didn't wont to work
So I retired it to the garage
About 6 months ago, whilst re-arranging the junk , I decided just to have a look at it again..
Guess what...It booted up and has been working properly since then
It's still running win98SE for the Kids games

Anyway, I hope you make better progress than I had

Xena