I've tweaked 2 Thomson drives and it works great. Boots every cdrw I've put into since, it was really finicky before. I won't take any responsibility if someone screws their drive, that's their risk...some ppl just don't want to swap out their dvd drive for a PC dvd and I can't blame 'em.
I suggest that you have a friend hold the probes on the multimeter and turn the screws yourself to get a 'real-time' reading, the pot is really sensitive (at least on the Thomsons) There are some people who say they don't have problems reading any media with the philips...I dunno, just do whatever ya'll want....