Replacement Power Supply Upgrade for Compaq HP PS-5251-4 Compatibility Compaq HP PS-5251-4 Output Wattage 420 w Connectors 20+4 Pin Motherboard, 4-Pin CPU, 2x Molex, Floppy, 2x SATA Cooling 80mm Cooling Fan w/ Double Ball Bearing Input Voltage 100/240 V’