I have a e-machines desktop PC, i went to use it the other day at it just wouldn't work having been fine the previous evening. The indicator light below the power on button it continuously blinking as is the green indicator light on one of the CD drives, there is a whirring sound although it is trying to read something but there is no disk inside and i hadn't been using one when i used it last. the drives won't open and the monitor says 'no signal' when first powerd on, then goes balnk. I have called the service team that i have a contract with and they are sending me a new video card, i have no idea how to replace this and whether or not this is the trouble, i am not convinced. Does anyone have any ideas?