This is a common problem with the W-2646 and its T- counterpart. The problem is usually with the motherboard, not the power supply, and not the fan.
Usually we have good hard drive, good memory, good components in the pci slots.
The problem seems like it is in the power supply, but after long testing with the involvement of a testing lab, we are certain the problem is in the motherboard, and the board failure causes the power supply to go out.
Complain to Wal-Mart where you bought it in writing, to help the next person.
You will go through a period where it almost works and has intermittent failures... but it will eventually crash and never start up again.
You can replace the motherboard at
www.eMachines.com for $159.95 but there is no guarantee that the same problem will not rear its ugly head again later.
If you don't use an eMachines motherboard, the recover disc for windows will never work for a reinstall.
You may have a lot of trouble trying to get the existing hard drive working again with another non-eMachines board, because Windows will detect that there has been a hardware change and refuse to boot.
If you are clever, you can call Microsoft to restart with the new product ID code, and be on your way with the Certificate of Authenticity found on the case. Do not do this online... only by phone.
But if you are just unlucky, Microsoft will not honor the install if it is on different hardware.
The Microsoft Official Position is that the Windows install dies with the motherboard.
You can but that hard drive in another computer, and use a full version of Windows (not a recovery version and not an OEM version) in R or Repair mode using the eMachines Windows Product ID, and get it running just fine in most, but not all, cases.
Good luck to you. Please let us know what happens.
We now have nearly 300 eMachines with similar problems as we try to force eMachines and Gateway in doing right for their customers. If that does not happen, we may go legal on them.
Because they know there is a problem... have known for three years they have a problem, and have yet to do anything to correct the problems on at least 14 motherboards... or notify the users they are about to lose their data.