_,,,^..^,,,_ said:

I thought to do this: capture the test disc, then capture the LD; switch off everything, capture the test disc, check if the phase is inverted; if so, I continue and capture the LD, if not, I repeat until the phase is inverted. This is the best technique I have in mind... the only downside is I have no PAL test disc, so I can't apply this to PAL LDs... (**/)

This technique would probably work just fine. I haven't tried it yet, so I can't make any guarantees, of course.