When it gets to that stage, I reckon professional repair will be required. It may get costly.
Have an Emachine. Connect power cord and lights on motherboard come on but when pressing power button, nothing happens. I was thinking if the power supply was bad light wouldn't come on. Could it be the power switch itself. Also before this happened I smelled some kind of burning such as electrical surge from the system and then it turned off. Ever since I haven't been able to get it to turn on.