However, the reason you use variable potentiometers is that every PS2 need individual adjustment, so you cannot just use one reference value. What you need is an oscilloscope and/or a laser power meter to measure what is going on when you turn the pots. It is always best to measure on a brand new well working PS2 to get some reference values to use when you are calibrating a bad laser.
If you have a laser power meter, you just have to put the photo-detector directly above the laser lens and look at the readout. If you are using an oscilloscope, you have to know where to find the RF/Eye Pattern measure points.
Laser potentiometers on the PS2 locations are as follows:
This is a picture from the underside of the PS2 Laser. The pots are marked on the picture. Turn clockwise to increase power and counter clockwise to decrease power.
Do not turn these wildly, or you might kill your laser by using too much power, or just be unable to get back to a working setting.
Now, get your scope and connect it to the proper test point. You also need to find a good ground connection, if you do not know how you should not be reading this any further.
