No video output....eh?

August 19, 2009 1:02 AM

Why is my computer not producing video output? (Normal start up sounds, stopped working while I was away)

Before I went on holiday I shut my computer down normally, I came back and now my PC produces no video. I've changed monitors and leads. I've also put in a new video card and that won't produce anything either.

It seems to be starting normally and the beep seems normal, HDDs etc seem to like normal.

My room might have got hot 30+ degrees while I was away. What could have caused this / how can I fix it?

(I know from experience XP is an nightmare when this happens!)

Any help much appreciated!!

posted by RufusW to computers & internet (7 comments total)

Does your PC's motherboard have both an onboard video card and the ability to use a card? Maybe the BIOS got reset and it's using the onboard video. I'd assume you probably already tried plugging into its DVI/VGA port though. Just a sanity check?
posted by floam at 1:30 AM on August 19

When this has happened to my machine, I usually do the following (in order):

Boot machine while the 'insert' key is depressed. Boot with 'delete' depressed. (Often this reset the BIOS);

Reset the CMOS (motherboard jumper, probably located near the button cell battery. Alternately, you could remove/replace the battery) (this also resets the BIOS);

Remove all add-in cards, disconnect everything except video and keyboard (including drives), remove all but one stick of memory.
posted by unmake at 1:43 AM on August 19

Yea, I've tried plugging the monitor into the motherboard (onboard video) and a new video card I've put in.

I'll look at resetting the CMOS, thanks.
posted by RufusW at 2:01 AM on August 19

What kind of video card do you have? I had a problem just this week where I had no video output... On my GTX280, a red light would come on when the video went out, and this indicates a power problem, so I think it may have to do with the ambient temperature combined with the power supply.

Haven't had the problem since I put an air conditioner in the window, though... I'm going to upgrade from a 700W to a 1000W PSU anyway and see if the problem is gone for good.
posted by Jinkeez at 4:14 AM on August 19

Try reseating your RAM chips, (or alternating them) if they're in a little funny, the graphics card does tend to break down. Though I'd expect you to be hearing a different beep-code on startup. Worth two minutes efforts to rule it out though.
posted by Static Vagabond at 5:23 AM on August 19

Okay, so I moved around the RAM chips and it's booted up now. I've got a single stick in now and if I add the other it stops working. So presumably it's a dodgy stick, or the mobo's decided not to recognise/accept 2*1G RAM. It's now running off the motherboard video - It seems it's definitely a RAM problem - you'd think it'd isolate this problem and give you a warning in BIOS - but hey ho!

Thanks for all the help!
posted by RufusW at 5:28 AM on August 19

Also, swap the damn cable.
posted by hexatron at 5:28 AM on August 19