How to make correct adjustment of CDM4

[DoctorWho70]

ok, your electronic is different from mine, but what you can see on page 10-11, regarding the sheets i sent to you, probably you have it in the card of your cd (a single card), in my cd there are many cards... but what you see on page 10-11 is probably the same that in your cd (if it's a cdm4) with the only difference that it is integrated in your main board.
so, read at page 45 about the regulations, and read also from page 40 to 46, giving an eye to the schematic of pages 10-11...
try to reconstruct your part of the schematic about your two trimmers and check if the circuits are similar.
if your mech is a cdm4 i'm quite shure that the circuit that controls the focus motor and the laser power need to do the same thing, also if the circuit seems to be quite different...
I don't know your cd, so this is the maximum help that i can give you.
Good luck
DoctorWho70

[henkel]

Dr. Who,

You have mail.

[SimontY]

Sorry to dredge up an oldie but I just searched for the information contained within this thread and am grateful to those who provided it. What I really needed to know was what CD to use instead of "test disc 5" and in the end I used a normal commercial disc.

My laser current voltage read about 53mV but my focus offset was reading over 7 volts and could only be adjusted down to 6.xxV. I think the 22K trimpot is bad! On a quick test it does seem improved by that small correction. It's not dropped out yet and doesn't seem nearly as bothered by floor vibrations.

This is in an original Arcam Alpha.

Simon