When i start up my desktop, it runs normally for about 10-15mins, then shuts off! When I immediately restart it after shutting off it just wont turn on! but then when i leave it for 5 mins it boots up sucessfully again but then shuts down again after 10 more mins of activity! All PM settings are disabled! Whats going on?
Well, I would certainly start by removing the CPU, cleaning off any old heatsink compound, reinstalling it with new heatsink compound, at the same time ensuring that the heat sink fins are not clogged up with dust etc. See what that does for the temp. Leave the core voltage alone for the moment. 59 degrees may be hot enough to make the CPU start acting weird. Give this a try and see what happens.