Hi, What I have do with a Dell DM/N Z670P-00 power supply is trying to connect each pin of the daughter board to either the +12V output or the ground output, through a high value resistor (above 120kΩ) while the power supply was ON, and read the voltage output, where was also connected a 12V 50W lamp. Until I found a pin that when connected to the + 12V the voltage drops to about 11V, so I tried to connect that pin to the ground instead, and the voltage increased to about 12.7V. I immediately saw the lamp becoming brighter. I then replaced the resistor with resistors of lesser values until I obtained about 13.7V with a resistor of 43kΩ. So I am now able to modify the voltage output from about 10.8V to 13.7V with a 50kΩ potentiometer connected to both +12V and ground outputs with two adjustable resistors in serial each sides. The problem with that method is that when I try to increase the output voltage above 13.7V (or lower it below 11.8V) then a protection circuit stops the power supply. (That's why I put adjustable resistors to limit the voltage change). If I now I add your two silicon diodes trick, I will be able to vary the output voltage from about 12V to 14.9V instead of 10.8V to 13.7V. If I put a switch to bypass the diodes then I can have both. It may be even possible to add more diodes and more switches.