Ok, so my 360 was running ok, as it has done for the past year and a bit. I turn it on today and it runs for about 3 hours, then the graphics goes all blocky and everything freezes. So I reboot it. It runs for 2 mins and it does the same thing again. Now if I leave the 360 for 10 mins, it will boot but after a few mins the gfx go blocky and it freezes again. Sometimes the 3 red lights appear.
...but again, if I leave it for approx 10 mins I can get it to boot again for about 2 minutes.
So I whipped the case off and booted it up. Again it ran for a few minutes then gfx go blocky and it freezes. I touched the heatsink on the CPU and it was failry cold. I touched the the heatsink on the GPU and it was HOT!!!
Does that sound like a definite GPU issue?
I proceeded to remove the GPU heatsink. There was no foil on it (as has been reported in other posts), so all apparently normal on that front. However (and this may be a red herring), I noticed that some of the grey silcon paste has started to drip towards the CPU heatsink. I stand my 360 on its side most of the time, so when the 360 is in that orientation it would mean that the paste has dripped in a downward direction.
Has anyone come across anything like this before?
If I pop to the local store and buy some good quality heatsink paste, is that likely to cure my 360's crashing issue?
Also, this may be completely unrelated, but I've also noticed something crusty and white on the bottom of the motherboard. No funny comments!!! It only appears on the bottom of the board. I thought it might just be dust, but it is quite hard to scratch off. So, I thought maybe it is dust combined with condensation, but all other dust in the 360 (and there hasn't been much) tends to brush off fairly easily. Also, it appears in patterns, but the patterns don't match the shape of the metal it sits next (I.E. the metal of the case when it is all fitted together). Also, I am certain that nothing has been spilt into the 360. I've had it since new.
As you can see in this next image, some of the copper on the board has started to corode:
Is this normal? Has anyone come across this before? Is it likely to be related to the fact that my 360 is now unstable???
Any thoughts or suggestions on anything above will be much appreciated!