Ps2 v9 laser calibration

[ottoman]

Had a problem on my version 9 that it was losing the ability to read dvd-r (ritekg4) so decided to do a laser cal yesterday.

Firstly measured the coil resistance and found i had a cheap nasty laser (coil 1 - 4.5 ohms, coil 2 - 0.9 ohms) so was glad I'd done the romeo mod.

Measured the dvd pot resistance which came in it 1175 ohms ( on the low side considering its usually 1200 to 1400 ohms).

Went to the white cogs. Put in an original game and adjusted both ways until the laser wouldn't read an original ( i.e too close or too far from the disc). I got a range of about 15 cog clicks where the laser would read dvd originals. Then went right across the range a click at a time (on both sides) with a backup and found no position that it would read dvd-r.

Turned down the pot by 25 ohms and repeated the cogs again, still no joy. After I'd adjusted the pot by 100 ohms (approx 10%) was still getting no dvd-r reading and am now loathed to adjust pot any further as it gonna blow the laser ( current setting is 1075 ohms).

Is there anything else i can try (apart from changing the laser) or is it time to unmod and sell on as a standard s/h ps2?

Thanx in advance for any replies