serious GPU overheating problem

[orelki]

My GPU is overheating. I have a Geforce GTX 460 and it won't stop overheating, it's 40-50C while Idle, about 60C when I watch HD videos in Youtube and spikes to about 90C and crash when I play video games. I dusted it, the fan is and was spinning just fine all along, but it would still crash eventually, with a brief sound loop and a "no signal" on the monitor...
It's a secondhand PC and I noticed that whenever the resolution is not 1366X768 some corrupt pixels show, the lower the resolution, the more pixels show up, maybe I need to buy a new one? I'm a little short on cash so I'd really like to fix this one instead.
Thanks in advance!
orelki.

 

[plaintuts]

for the sake of hoping that your gpu is not broken.

you can improve air circulation in your case by adding additional fans if your chassis allows it.
for cleaning the gpu, it's recommended to use a can of compressed air to blow away the dust stuck deep in the Gpu. or you can use an air compressor but not with a strong psi.
you should also clean the entire computer from dust.

lastly, if you can use your computer in lower ambient/room temperatures, somewhere with an air conditioning unit, the better.