I have an X5DA8 motherboard and an SP401-RA(12V) 400W power supply. The system uses 2x Xeon3.06G CPU, and all 20-pin, 8-pin and 4-pin power cables are plugged into the motherboard. The system keeps giving me beep warnings and the onboard LEDs are red. If I change the power supply to your SP420-RP, there's no problem. What is the problem?
The SP420-RP auto-senses the input voltage while SP401-RA(12V) does not. Please set the input voltage to 115V in the rear of SP401-RA(12V).