Have you tried manually resetting the power supply On/Off switch on the outside of the case?
If connected to a surge protector/power strip with a reset button...have you tried that?
There isn't an On/off switch on the power supply, just to change the voltage.
I've tried different surge protectors, and have since got a UPS backup for when I get it working again.
A little more info: Most surge protectors are only good for one or maybe three good surges before they are useless. The better surge protectors have indicator lights to tell you if they are still active. Also, most surge protectors don't do squat for brown outs, unless they specify that they have some sort of line conditioning. Most good power supplies also have some sort sag protection built in. I'm also not sure how long you've had this machine, but apparently, a couple of years ago Emachines had some faulty motherboards, I'd check to see if yours wasn't on that list from Emachines.
Thanks for the info, I just got a UPS backup, so hopefully this won't happen again.
I've had the machine for a couple of years, where do I find this list?
Emachines usually have Bestec power supplies
Bestec PSU's are best known for frying the motherboard when they go out.
[Which is usually a little over a year].
The computer should have a standard ATX power supply.
Pop it open & see what kind of connections it has for the drives , SATA or IDE, & get a replacement power supply with the same connectors.
I suggest at least a 450 Watt [or higher] power supply.
What is a good brand of PSU for a replacement?
Also how do I tell the difference between SATA or IDE? It's been a while since I've done anything with hardware outside of a RAM upgrade or card installation.