maybe its just because its summer, maybe there is a process that is using your cpu intensely. if dell replaced EVERYTHING, mobo, power supply, fan, what else could quiet it down? you could replace the cpu fan yourself with a quieter one.
My Dell 3000 is just over 3 months old. You could not hear a sound while the computer was on.
Recently the fan began to make a louud noise.
Dell service came and changed the Power Supply. The noise continued.
Next they changed the Fan. After a few days the noise continues.
Next they changed the heat sync on the mother board. The noise contunued.
Next they changed the power supply and the mother board. the noise continues.
I had a Compaq, Dell, E Machine, Acer and Gateway and none of my previous machines ever made such a loud noise. What should be my next step