I have searched the forum for similar posts and there was a thread with the exact same problem as mine but it wasn't resolved. My dad's Emachine won't switch on. I opened the machine up and found that the power supply appeared to be recieving power as the small green LED on the motherboard was lit. But nothing else happened at all. No fan, HDD or anything else. From what I have read on this forum this may mean the power supply is dead (or maybe running at a low voltage?). Or the mobo is dead (apparently very common for the dreaded emachines!) I really don't want to have to buy a new Power Supply before finding out it is the mobo (and why would the green LED on the mobo light up if the power supply was dead?) I heard there are some other things I can try before this but what are they? Also, in the process of trying to eliminate the on/off switch from the cause, I unplugged the 3 leads at the front of the case (the HDD LED, power LED and S/W Power) from the mobo. Unfortunately, I thought they were one plug and i didnt really pay attention to how they were aligned. As some of you will know - these were actually 3 separate plugs and now I have no idea which way they plug back onto the 5x2 pins!! (The three cables are black/white, green/white and red/white). Can anyone tell me which way to put them back (I reckon it may not even matter which pins the plugs go onto as long as I have the polarity correct - i.e should the white wire of each plug go into the top or bottom pin?) All help is greatly appreciated!