I cut and pasted the following from:
http://www.jordanrudess.com/forum/showthread.php?t=2985
WARNING NOT RESPONSIBLE FOR ANY HARM YOU MAY DO TO YOURSELF OR YOUR
KEYBOARD!
The battery on my PC88 died...only intruction I found was to take it
to a service center -- BAD.
So, Here's how I did it.
Turn the PC88 upside down (keys on bottom). Remove all the screws on
the bottom (which is now the top) of the keyboard. Also, remove the
screws on the back which are all in a line on the back (seven of
them). Also, remove the screws which hold the end caps to the bottom.
There are some on the bottom (which you removed) and two on the back.
After this, you can lift the bottom of the keyboard up slightly. You
will probably do as I did and accidently remove a ribbon connector
which has very little play (controls the bottom range of keys on the
keyboard). Don't worry, you can plug this back in later. You will
see on a circuit board the battery. Believe it was a CR2032 (not
sure). I bought a replacement battery at Wal-mart. Gently pull the
battery out and pop in a new one (the positive side of the battery
will be facing away from the battery holder, only partially obscured).
If the ribbon cable popped out, lower the bottom of the keyboard
closer to the assembly, and gently plug it back in.
All that's left is to put the bottom back on, aligning all the screw
holes with their mates. You may have to align the controller wheels a
bit so the holes are realigned, but this wasn't a biggee.
Took me about a half hour because there are so many screws holding the
bottom on! Battery replacement took five seconds
elbolabs
************************************************** ********
My thanks to "elbolabs" for providing these instructions. I did this last night and will provide some additional guidance.
First, 'elbolabs' was correct. The battery was a CR2032 which I also purchased at Wal-Mart.
Second, the battery is located right behind the switch pedal jacks. It stands upright in a black plastic holder with a top lip that can be pulled back to allow the battery to be lifted out. You'll need long fingernails or a small screwdriver (i.e. jewelers size) to help lift it out.
I followed 'elboblabs' instructions on replacing the battery on my PC88MX. But it was pain to align all of the screw holes for the components underneath the housings. Especially on the left side where the controller wheels are.
My PC88MX had never been opened before. Besides the seven plus four screws that 'elbolabs' mentions, it had 23 screws on the bottom that had washers. It also had 8 screws without washers, four on each end. The screws holding the controller wheels were smaller.
I then changed the battery on my friend's PC88. It had a few less screws to remove but was basically identical to the PC88MX. I'm not sure if the fewer screws were the result of the fact that it had been opened up before.
Since I knew the location of the battery, I decided to loosen but leave in the screws on the left side of the keyboard (low notes) where the controller wheels are, including the controller wheels themselves (four screws).
This allowed me to lift the housing just enough, allowing the housing to pivot/hinge off of those remaining screws, so that I could gain access to the battery, and still keep that end aligned.
Once I changed the battery on the PC88, putting it back together was much easier given I hadn't disassembled the left/low end.
Given the advanced warning from 'elbolabs', I was careful and did not accidentally disconnect the ribbon cable.
I used my Makita cordless drill/screwdriver which made the screwing effort go much more quicky. I also used and would recommend a blanket or something to protect the surface of the keyboard while upside down.
In case you've misplaced your manual, to check your battery level, press the 4, 5, and 6 buttons simultaneously. The "B" setting should be 2.8 or higher. If 2.4 or lower, the battery should be replaced. After replacing the batteries, the PC88MX read 3.1 and the PC88 read 3.0. Pressing Cancel and Enter simultaneously returns you to normal operation.
Hope this helps! -
Jim
