AMD Athlon XP 2700+ /1GB ABIT NF7-S MOBO 400W PSU Coolermaster CPU FAN ASKA 768 CPU FAN I have been building a pc for a mate, i finished the build, started up the pc, it run for a short time, then turned its self off. I then checked the power supply and cpu fan, i applied additional thermal compound to the cpu. the pc run for a bit longer, but still turned its self off. i changed the cpu fan from the cooler master, which had been in a working Athlon 1800+ pc,for the aska one, but this only made the pc turn off after a couple of seconds. someone plz help!!!!!!!! The simplest solutions are the best and they are often save you money

Are you aware that it takes a very thin layer of thermal paste to get the best results?

"i applied additional thermal compound to the cpu" Additional compound? You only need a small dab roughly the size of a grain of rice. More is NOT better. Are you sure the heatsink isn't installed backwards? What are the system & CPU temps? Are you sure all the BIOS settings are correct?

"Are you sure the heatsink isn't installed backwards?" The upward notch in the heatsink must be over the raised part of the socket on the one side of the socket - if it isn't the heatsink cannnot sit flat on the cpu core properly and the core will overheat quickly.