Marantz CD65II - Help please

[Perofrka]

Marantz CD 65II from my friend stop working. CD rotating anticlockwise and laser head stuck in the centre. I found some schematic of various CD players and chips on net and try to locate a problem. Finally I found a BC 338 in power suply which give +3.5V where I expected -12 V. I replace it with BC 337-40 (cannot find 338) and now CD rotate in right direction and laser head try to read disc. Some discs is recognized and some not so I think I must adjust 2 trimers on board (22K and 4K7).
Questions:

1. is a BC 337-40 good replacement for BC 338

2. does someone know how to adjust 2 trimers (how to enter service mode and how to measure)

3. found 3 opamps (4560D JRC 8031 and 2xLM833N). The first one may be used for headphone output and the LM for audio out. I think to change them for better once but i find only NE 5532 in shop. Is NE pin compatible and will they give sound improvement over LM.

Thank's for any help and sorry for my poor english.

Pero