For a lasting professional repair, tweaking the laser power pot is never a
recommended strategy for the short term failure reasons that you state.

Yep. However, there are three adjustments on most cdrom drives. The
laser current is not available on all models. However, there are
adjustments for the focus coil bias (sets the height) and servo loop
gain (sets ability to track warped disks). Both of these can be
adjusted to compensate for "normal" mechanical wear. See:
http://www.fortunecity.com/meltingpot/india/245/index5.htm
http://www.repairfaq.org/REPAIR/F_cdfaq7.html#CDFAQ_005

There are a few exceptions to this rule - notably Pioneer lasers - where
setting the laser current is an official documented part of the overall
setup procedure.

Umm... I don't think Pioneer has an accessible laser current (power)
adjustment. (I don't have a schematic or manual to be sure). I
couldn't find anything in Pioneer section of the RepairFAQ proceedu
http://www.repairfaq.org/REPAIR/F_cdfaq8.html#CDFAQ_014

I was talking more in terms of CD player lasers when I referred to Pioneer.
On almost all of their models, adjustment of the tiny laser power pot on the
flexiprint that goes down to the main board, is a proper part of the
adjustment procedure. I was just trying to convey to to the less experienced
readers, that it is an exception rather than a rule, to adjust laser power.
I was interested to know exactly what wear you feel warrants adjustment of
the focus bias (offset) ? I would agree that it doesn't hurt to slightly up
either tracking or focus gain, to improve 'playability' with some discs. The
setting of these controls is something of a 'manufacturing compromise' in
the first place to ensure that the servos have sufficient gain to maintain
lock under all conditions, without causing the lens suspension and drive
coils to 'whistle' too much on marked discs. However, short of serious wear
in the spindle motor causing the turntable to drop, I can't think of any
wear that would indicate a change in focus bias being needed ? The focus
servo has a pretty wide 'window of lock' anyway to accommodate warped discs,
so tiny amounts of wear in the motor will not have a lot of effect on the
nominal focus point.

Arfa