ORIGINAL: K-OS
Just did the mod on an Antec 400 watt power supply. When I connect the charger while the unit is on, the unit shuts down completely. However when I connect everything and THEN power on the unit it works.
Just wanted to share this info so no one does the same mistake as me (dismantle the unit 3 times and try over and over)
This is a fairly common occurrence and is tied to the overload protection circuitry built into the PSU. Some chargers have fairly hefty ripple suppression capacitors built into the front end and when discharged represent a significant current sink when attached. To the PSU, this is sensed as a short and it latches off. However, because most motherboards are populated with a large number of capacitors, the Design Guide states that PSU's should be able to power up with an attached 5000 uF load on the 12v rail and stabilize.
When the charger is attached first, the load seems typical and the PSU comes up to full power. When attached later, the high current sink is atypical and the PSU shuts down.