Emax

Hello.

Recently purchased an Emax II on Ebay.  Model 2212.  I have a few questions:

1.  The topmost C key is partially broken.  Can this be repaired?  Is there 
someplace I can buy a single key, or would I need to replace the entire 
keybed?

2.  One the main CPU board (Emax II CPU VERS 2 PC360 REV B.1) I noticed 
several missing ICs:

IC4: located 2 IC right behind the external SCSI port
4 banks of 8 sockets each on the far left of the board.
there are 2 blue connectors on either side of these sockets: labeled CN12 
and CN10

I also noticed several empty places on the mainboard where a chip could have 
been soldered but never was.  There is a large one right next to the large 
chip marked "E-MU IC368-A" in the upper right of the board.  Did Emu use the 
same board for different Revs of the Emax II and/or the Emax I?

3.  My sliders seems a little scratchy.  How to go about cleaning them?

4.  On the Analog PCB, there is an empty socket labeled IC9.  What is (was) 
this for?

5.  I am not sure if my transpose button is working.  How can I go about 
checking, and if it is broken, how to fix?

I emailed this list recently inquiring about an Emax I.  Since then I have 
got my hands on an Emulator II, so I decided to go for the Emax II because 
of its SCSI capability.  The Emulator is in the shop getting an overhaul, so 
I have got plenty of time to become acquainted with the Emax II.

Much thanks for any answers to my newbie questions.

Dan