Fans spin and then stop spinning
I have an xbox 360 which keep getting the RROD, I clean the gpu and the other chips and place a new set of thermal paste on those chips. I use artic silver 5, after all this is done, I power on the xbox 360 and the fans spin, then the RROD appear on the front of the console, I know the fan is not bad, because I swap it from another xbox that is working fine, I am wandering, could my heat sink be causing this problem, since ther RROD is normally a sign of hardware failure, thanks for all your help.
In theory, yes it could be. In all reality, you have not fixed the problem. The heatsink may still not provide enough heat dissipation and you may still have a GPU that does not make proper contact. That is what the clamps as supposed to assist with. A re-flow of the board would, for the lack of an easier explanation, re-solder your GPU. But the clamps can provide enough downward force of the GPU to assist to make better contact with the logic board. I hope this makes sense...Good Luck and the RROD kit is available here
Fix kit for Xbox 360 consoles with the "Red Ring of Death" (RRoD) failure. Replace, reattach, and reclamp the heat sinks on your Xbox 360. Usually fixes a RRoD Xbox—also effective as a preventative measure. Kit includes: tube of Céramique 2 thermal compou — 10 available at 29.95 each.
I really can't tell what kind of problem you have. Is your red ring "half-full" or is it "three-fourths-full?"(I'll Assume This)
Not every RRoD is caused by a problem with the GPU and CPU. If you aren't the original owner of the console and don't know it's repair history, it might have a problem somewhere else, such as a damaged diode, or broken traces on the motherboard. You should look around the motherboard for damage to to any of the circuits, or scratches that may be breaking traces. You should also inspect the CPU and GPU for cracks, and scratches, as these may cause problems too. Also, for your X-Clamps, you need to have two washers(Not One!)between the motherboard and heatsink for each screw.