So when my latitude e6400 is running on battery with no lead plugged in, after a couple of minutes i get a loud crackling/rumbling sound from the speakers and the screen freezes, the sound of crackling/rumbling then continues every few minutes however the computer remains frozen and can needs to be restarted via powering off and back on using the main power button. This also happens when the power lead is attached however less often (until recently, now it happens as often as when unplugged). This is a persistant problem and happens every time i turn the laptop on.
I thought it could be a fault with the hdd, so i changed that and it still happened. I've tried it with several versions of windows and it still happens, i have tried not installing any software but windows, still happens, i have tried upgrading the ram, still happens.
Has anyone come across this before?
I'm thinking it may be a power issue, however the screen stays on and the power light stays on while this happens.
Anyone?