I have replaced the Power Supply to be a larger one. The mother board is a PC CHIPS M811LU ATX AMD Motherboard. The processor AMD XP Althlon 2000+. The memory is Elixir 256 MB DDR. Nothing happens when I hit the power button. No lights not action nothing. The computer is only about a year old. I have talked to Tech Support for the mother board they thought the Power Supply might be bad. Now I have changed that from a 300 watt to a 420 watt power supply. I am getting the same results.