While using the computer like I normally do the screen suddenly went blank with a message saying no signal, but my computer is still on. When I turned it off and back on it made a beeping noise but the screen was still blank. After turning it back off and on again it can get as far as the Windows loading screen before the screen goes blank with the no signal message.

My computer uses Windows Xp Home and has an Ati Radeon X700 graphics card.

Currently I'm using my Wii to post this.

Does Windows load in safe mode?

The same thing happens in safe mode.

I've had this happen about half a dozen times. My LCD just displays the no signal messag,e the game I am playing is still running fine, but I have to shut down/restart to get it to work again.

I can't even get as far as play a game. It goes blank as soon as the log in screen appears.

My computer is five years old, and my mum thinks I should get a new one.

It's probably your graphics card Chuckchi. That beep error code was your motherboard telling you it couldn't detect a video signal. You could replace your graphics card, but with a five year old computer who knows what will burn next. You might want to get a new one and just toy with your old one to see if you can get it up and running again.

The graphics card was one of the newer parts of the computer, less than two years old. Before it only had onboard graphics that had problems running many games and used shared memory. I thought that if it was the graphics card that I could buy a new one to replace it, but I don't know if there's much point because of the age of the computer.

I don't know when I'll be able to get a new computer.

Have you tried pulling out the graphics card and then booting in safe mode?

I haven't tried it yet, but the last time I upgraded my computer I tried to take it out (because I thought about replacing it before when I saw a really cheap graphics card that's newer than mine) and it seemed like if I tried to take it out it would snap.

There's usually a little plastic lever at the bottom of the slot that holds the card in the slot. If you depress that lever with a screwdriver (be careful) you should be able to wiggle the card out of the slot.

It was a button. I pressed it and took the graphics card out. When I started the computer in safe mode using the onboard graphics it was working. I discovered the reason why the graphics card wasn't working, the fan was full with dust. After cleaning it out, it was working again, and quieter.

Great. Too bad you won't be getting a new computer though.

A new problem now. Now the computer loses signal randomly, sometimes at the log in screen, sometimes while in the middle of doing something, but yesterday I played a game and there was no problems.

Pull the card out again, and check if the contacts are clean.

I tried cleaning it out again, but using a pump to blow it out. The dust came out like smoke clouds, and the pump turned grey.

As Rheinmetall said, check all the contacts leading to the card, and blow out the PCI/AGP/PCI-e port ( whichever one it is that your video card plugs into ). I also hope you held the fan down while blowing out the dust, because, while it would be pretty hard to over-spin it with a pump, if you used one of those compressed air cans, you could have spun it too fast and damaged it, leading to your video card now constantly overheating. Just to be sure, crack open the case, and run some gfx-heavy program, and check if the fan spins.

I didn't hold down any of the fans. It wasn't a compressed air can, it was a pump used to inflate things.

I did play Sid Meier's Pirates and I worked for a few hours.

Now my computer doesn't work at all. Once I turn it on it stays frozen on the first screen before the booting screens.

Even with the addon video card pulled out?

I haven't tried that yet.

I removed the graphics card, and the computer is working again. When I put it back in again I forgot to put in the power cable and it came up with a "no power to video card" warning. I plugged the cable in and the computer stopped working again. I removed the card now.

Would it be the card or the AGP slot that's gone wrong? I think it could be the card because of the warning, but I'm not sure. I don't want to buy a new graphics card and find out that's not the problem.

The cheapest ATI AGP card I found was £50, but there are a lot of GeForce cards for cheaper. What would be the GeForce equivalent of a Radeon X700?

Any 6xxx series GeForce card. Do you have another computer where you can plug the card in? Like a friends or family members computer. If it works on theirs, then its your mobo, if it doesnt, its your video card.

There isn't another computer I can try it on.

Do you only have one AGP slot on your MOBO? I think you will find out that it was your card and not your mobo. I also think that the constant overheating that you were experiencing might have burned out your card.

Without another a computer to test it you have a few options. Take the card and the computer to a local computer shop and have them test it for you.

Buy a new card and hope that it is only the card.

Forget about this computer altogether and buy a new one.

It only has one AGP slot. When I go into device manager it says "the device is working properly", would that help?

Underneath the AGP slot I have an empty slot that I can't use because of the graphics card. If I remove the panel for it would it help with ventilation or should I just leave it?

I saw a GeForce 6200 for £30 (the cheapest non PCI-E I could find), so I could get that. I can't get a new computer at the moment because it's too expensive, and I think the price of the card is less than the price to take the computer to PC World for testing.

As far as I know, there is no mobo with two AGP slots available today, or ever was for major consumer distribution...And what card do you have right now? a X700? the 6200 will give you much worse performance I would think...

It only has one AGP slot. When I go into device manager it says "the device is working properly", would that help?

Underneath the AGP slot I have an empty slot that I can't use because of the graphics card. If I remove the panel for it would it help with ventilation or should I just leave it?

I saw a GeForce 6200 for £30 (the cheapest non PCI-E I could find), so I could get that. I can't get a new computer at the moment because it's too expensive, and I think the price of the card is less than the price to take the computer to PC World for testing.
There aren't any local, small shops around? You don't have to go to a giant chain. Take a look through your local business directory and give 'em a call.

The next cheapest card is a Radeon X1550 at £50, but it might be too powerful for my computer, and it's too expensive at the moment.

There isn't any small local computer shops around where I live.