I need to find a replacement for:
Power Tek Switching Power Supply
Serial # L053003
Input:
115-6A 6Hz
230V-3.5A 50
Output 500W
PowerTek site says not available.
Computer is 7 years old.
Merry Christmas!
Welcome to HWF 
Most power supplies are universal, so you can basically use any ATX power supply. We have a purchase guide here: http://www.hardwareforums.com/power-supply-sticky-5218/