Teardown amount 400 capacitor voltage, the insurance has serious black, this is followed by a short circuit, the result is 400 rectifier piece of short circuit, in after the power supply has not started, consult the starting resistance value without change, check the other small components, suspected power brick DP704C bad, in after remains the same, in fact DP704C or bad, because I later compared with both feet have short circuit between the original DP704C multimeter. Due to previous original checked before the transformer, again doubt light coupling, remove the quantity with one end has the leakage, in 708 after the start-up, commissioning normal connected to computer.yuLservice manual download site