A friend of mine has two intel motherboards of a Dell Precison 470 which is acting up. There was a malfunction which he doeasn't know what he did but when he tried to turn on the computer it wont turn on. We thought it was the memory since POST was not responding so we changed the motherboard but nothing happened. We dismanted the IDE's but still nothing is happening. We tried the memory on a working computer and it worked fine so did the other components except of the processor but we checked and found no damage and the heat sink and the fan works okey.
What could the problem and how can it be fixed?