HELP Sony cd changers are skipping

Hello, I need HELP!
My Sony ES cd changers are skipping right
around 4-30 seconds into playing ALL cds.
First, what could be causing this
to happen?
Second, can I fix this, rather than take it
to a dealer and wait 2-3 weeks to get it back,
and get charged a ton of money?
Third, does anyone here have a Sony Service
manual, that I can use IF I can do this?
Forth, I know someone on here had the same problem
like 2 months ago, but I can`t find the thread.
They fixed it by using WD-40, can WD-40 be used
to correct this issue?
The model of cd changer is a CX90ES, or CX70ES,
or a regular CX270.
I might have found the thread you are looking for....
Also, I need a service manual, because
on one of the cd changers, the right
channel does not work!
I think this was caused by using the
Monster Cable DEATH GRIP cables, and both the
left and right outputs on the back are lose!
Please let me know how I can fix both of
these problems without paying $300 per changer.
Just to say I have used Sony ES changers for many years. First was a CD89ES, Then 2 CD9ES now I still have the (slighly misfunctioning 9's) and a demo SCD333ES.
The problem I have had is never the laser, it's the flat cable from the laser sled to the rest of the electronics.
That cable is flexed every time the player changes CDs, and the connection fails intermittently (while in play) as the cable is flexed .