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Kurzweil PC88 Battery change

chisteve1975

Hello, my kurzweil PC88 that my predecessor purchased is saying it needs its internal battery changed and now it will not turn on. Is this an easy fix? I cannot seem to locate support for this in the instruction manual. Any advice would be helpful.
Thanks!
October 26, 2005 @09:03pm
KORG TRITON

If the internal battery is dead, it will still power, but your own settings will be killed, and storing sounds and anything on it will be impossible, take it to a shop first before replacing the battery. The shop has to replace the battery.
August 10, 2006 @07:28pm
Mainframe2010

A good description of how to change the PC88 battery can be found at the Richmond Mainframe site at the following URL:
http://www.richmondmainframe.com/kurzbatt/
June 10, 2010 @09:11pm
jasper

Elsewhere on this site is a link that graphically indicates which screws and where they reside need to be removed to be able to change the CR2032 battery. I searched the web and found this was the best info I could locate. Although the locations are not exact, they are close enough to be able to perform the battery change effectively.
Here is the link of the previous post:
http://www.richmondmainframe.com/kurzbatt/
I have both a PC88 and a PC88mx I purchased within the last 2 weeks.
The PC88 battery tested at 1.2 Volts. It was so low that the built-in diagnostics (1-2-3 buttons pressed and released at power up) would not run, display was all red color.
Since my background is in electronics, on both units I plan to buy a 2032 battery case from eBay. Search on some terms below:
"2x CR2032 X1 Button Coin Cell Battery Holder Case Box 3V Wire Lead ON/OFF Switch"
(There are other battery cases available, but beware cases that hold 2 CR2032 batteries. They come configured to produce 6 Volts and all that is required is 3 volts).
The case I indicate above also has a switch, although not desired, once set to "ON" it should be fine. (You could check with an ohm meter or battery tester...oh yeah, the Kurzweil PC88 can measure it also with a 4-5-6 key press later). The case will hold 1 CR2032 lithium battery and has some short red and black wires for electrical attachment.
The real issue is that it is awful complicated to change the battery...the location is just wrong and getting to the battery is difficult. I looked at a number of possible solutions for the next battery changeand the best one I have come up with is to relocate the CR2032 battery to live as part of the pitch wheel assembly which is easily removed, just need to carefully route the cables.
I RECOMMEND HAVING A FRIEND FAMILIAR WITH SOLDERING AND VOLT-OHM METERS if you feel you are not up to it...2 wires need to solder to the original holder and would be best if a battery could still be installed (for I/O board service reasons only).
-disconnect power to the PC88 and disassemble as per the "richmond mainframe" link above. (print out all 3 pages ahead of time)
- remove the on-board CR2032 battery from the I/O board and dispose of it.
-solder a twisted set of red/black wires (4 feet ought to be enough, and the wires don't need to twist...even an old 10/100 network cable will do...just need 2 wires) to the contact points of the on-board battery holder (red to the + side and black to the negative side of the battery clip). The CR2032 battery delivers micro amps, so the thin wires ought to be fine. (The CR2032 is commonly used in some laptop computers for CMOS settings and some of them have thin wires attached as well)
Carefully study the best way to route the wire toward the pitch-wheel area on the left/front side of the keyboard. Use some of that tape with the stringy stuff in it (just like Kurzweil used for some of their other cables inside, reinforced packing tape will do). MAKE SURE that you are not trapping the wire or squeezing the wire underneath any of the metal rails when you reassemble.
I will be using some plastic wire covers known at the auto stores and electrical stores as "split loom" for running wires inside of the loom/wire_covers/protectors.
Now the twisted set of wires are routed toward the left end cap, remove the 4 screws (smaller than the rest) in a square pattern that holds the pitch wheel assembly to the base. CAREFULLY remove the assembly noting that there are 3 cables to be addressed: (2 are delicate)
1 cable is thick and sturdy and plugs into the rear electronics board, but also plugs into the pitch wheel board.
2 more cables are flat ribbon type (mine have 2 blue 1x4 connectors). Get a permanent marker and make some identifying marks on those connectors (I used "R" and "L") such that you can reinstall them correctly...mark them as you disconnect them from the pitch-wheel assembly.
Using some shrink wrap tubing on the next step (or other connector scheme one might use to hook up auto speakers with)...don't leave any connection exposed, especially the “+” or red wire.
The very best option is to use a polarized set of connectors located relatively close to the pitch wheel assembly....if for example a shop works on this later you can give them a way to disconnect the rear electronics section from the base cabinet and keyboard section without removing the new battery holder from the pitch-wheel assembly.
Solder (or connector method) the two black wires together (one from the new CR2032 battery holder, the other from the old battery holder).
Solder (or connector method) the two red wires together in the same way, insulating the wire connections. I prefer soldering.
If you used connectors, tape them down so they don't rattle.
All that is left is to attach the new coin holder to the back of the pitch wheel assembly and make sure a new battery is installed inside the new holder. Use an ohm meter to be sure the + terminal of the battery will connect to the + terminal on the original holder. Tie Wraps or velcro wire wraps may work best. Study the pitch wheel assembly and you will see some options for attachment...there are some screws available that can be used. While you are looking at it you can tweak the metal holding the potentiometers a tad to get the plastic wheels lined up correctly (only pry metal case on metal case, not on plastic or on the potentiometer itself...fixed mine as the plastic wheels were dragging on the top plastic plate).
When installing the pitch wheel assembly, your unit is opened up laying on a thick large towel, rear electronics section flipped back and upside down behind the base case and left side panel needs to be removed for easy viewing (3 screws on the bottom of the left cap...the 4th screw was already removed flipping open the back case).
The idea is to be able to remove the pitch wheel assembly by itself and reinstall it without damaging the cables that attach to it.
Once you have done this remote battery mod, should the battery ever discharge, you only remove the 4 screws (the 4 in the rectangle pattern below the pitch wheel area, left front corner). The pitch wheel assembly can tilt upwards from the rear and slide back toward the rear a bit, maybe a quarter of an inch, (it is a loose mechanical fit) then carefully raise the assembly up. (Make sure power is removed from the PC88 when doing this and remember that some cables are delicate)...take care of the cables, switch out the battery....reinstall making sure no trapped cables....carefully add 4 screws without pinching or damaging cables and DONE...you can change the battery as often as you like and it won't take more than say 5 minutes.
While you are at it, you can avoid paying $5 for the CR2032 at the CVS or Walgreens by purchasing some of those tiny flameless candles at The Dollar Store...multiples for a Dollar and each candle comes with a fresh CR2032!
July 15, 2014 @10:06pm