From the day the very first Emachine PC hit my workbench there have been power supply problems.
As a matter of fact my floor is littered with Emachine cases from the first model to the present.
One thing has been a constant in all these years, power supply malfunction.
On some, the power supply blows the motherboard, on others it simply self destructs and the motherboard survives.
But the most common scenario is that both the motherboard and power supply die together. The problem is actually pretty simple, though still deadly for the hardware.
A typical cheaply made Emachine power supply will work flawlessly until one of 2 things occur.
1. you turn off the switch at the back of the machine
or
2. you unplug your emachine with it either running or off.

What happens is that your Emachine is in a constant warm up or (ready) state much like an instant on TV set. The power supply isnt actually on at full power but it's still active, waiting for you to hit that little silver E.
Most PC's are designed this way, but the Emachine has it's own idea of how things should be done.
Unlike a well made power supply, which will absorb and or bleed off the stored voltage from your motherboard capacitors when the power switch is turned off and the power button is pressed, an Emachine will not allow the excess voltage discharged from your capacitors to shunt to the ground which runs to your power outlet earth or ground wire.
Depending on the power supply used on your particular Emachine, the voltage may either accumulate in the power supply's larger capacitors and dump back to the motherboard which hasn't been turned on yet, not allow the capacitors to discharge at all, or dump their OWN high voltage capacitors stored voltage onto the motherboard itself.
This results in swollen or ruptured Capacitors and a dead or semi dead motherboard.
The solution is, and has always been, replace that power supply before it ruins your budget!
But on a lighter note, An Emachine makes a pretty door stop.