Believe me @sidehack, I did search to avoid such answer.

Now even after buying a good powered hub the 2pac keeps going OFF even after few days of running perfectly, with 2 fans directed on the single 2pac being used, I did try all sides of the voltage knob and yet I still get OFF issue!
Isn't there a more illustrated graphical guide to setting the correct voltage?

Or how do I detect the current-voltage needed for the 250Mhz or 150Mhz?