I have a n14-200p1a (adp-200er). It gives standby ok but when turn on, the pfc boost the capacitor voltage to 400V (but no 12v is generated) and the psu shutdown completely, even the 5v. I have unplug and replug the mains to turn the psu back on. Any idea where I should check? I checked all mosfets and diodes for shorts.