Monitor no signal help needed

[wolfiefish]

hello all.
I don't know if I have posted this on the correct forum, but it's all visual isn't it.
Ok, My Daewoo flat screen monitor has started to just go blank after a few hours of working on the p.c.
It goes black, and then a message appears saying "No Signal", ten it turns off.
I have plugged the monitor to my laptop and it worked ok.
What could be the problem?
Is it a graphics card problem? I have an Nvidia 128mb agp card,
Sometimes I can work for hours until this happens, however a month ago the problem repeated itself quicker and quicker happening all the time. I reformatted the p.c and the problem went away for a month, but now it's back. Arrrghhhhh.
Please help.
Do I need a new p.c?

Thanks all.

[Stalemate]

I'm guessing this happens while you're working on the PC itself.

I would suggest just cleaning the graphic card's fan and heatsink to remove dust and lint for starters, using a can of compressed air with the PC turned off and unplugged.

It seems like it's suffering from overheating.

[xpuser357]

You may want to upgrade your power supply too.

[wolfiefish]

My power supply.
I have always thought that this could be a problem as I have countless devices attatched to the p.c, and my power supply is 200 or 250w.

I have cleaned the entire contects of my p.c about 6 months ago, a thorough job was done, but I suppose I could give the graphics a card another clean.

I shall report back on my findings. At the moment the monitor is staying on as I only turned the p.c on about 30 minutes ago. I wonder when everything will go black again?

[SwAT]

It could be your refresh rate or the screen resolution. Make sure their isnt anything int the plug on both ends that could be interfearing.

[wolfiefish]

I'll check the plug.
I didn't think refresh rate mattered with flat screen, LCD monitors.
and for the res I select the compatible resolutions from the monitor List mode list.