My about 10 y.o. SONY har recently begun misbehaving, with progressively
worse skipping primarily when playing newish (Audio) CDs, the first
three (innermost) tracks mostly affected.

Last week I opened the cabinet for the first time since it was
assembled, discovering a very clean inside, with whitish grease still
neatly lubricating the interacting surfaces of the disk transport
mechanism. Only sign indicating use was on the inside of the cover above
the transformator, where a light deposit could be wiped off. I cleaned
the laser disk gently with ethanol, but found nothing else I obviously
could do anything with. Subjectively, I imagine a slight improvement in
the clarity of music played post-cleaning (but this may be a
placebo-like effect).


Make sure all sliding parts aren't sticking at the end of their range.
And make sure any rubber belts are clean and grease-free. Apart from
that, there's not much you can do without technical skills and
equipment. And if you had those, you wouldn't be asking here :-)

Is it a particularly wonderful player? The current sub-£100 Sonys are
really very good.