power supply

Hey guys, i have a harsh sound after switching from mains to battery power when only in a specific situation: disconect the mains power cable while in hibernation, coming back from hibernation (on battery power) the laptop makes a 1 sec. long harsh sound. Can it be the difference in voltage when...

Hey there guys, I've been trying to salvage my 8 year old Acer Aspire 4750G. Been having problems with it turning off randomly, even while not in use i.e. no prompted programs running - sometimes a couple of minutes after startup. Firstly, I thought this was a fan/cooling problem. Replaced...