Korg M1R Battery Replacement

Copyright c2009 Trygve Isaacson. All Rights Reserved.

Like most electronic equipment, synthesizers like my Korg M1R have an internal backup battery that allows its volatile internal memory to stay alive while the unit is powered off. My M1R battery finally died after around 15 years of service.

With the dead battery, all program memory is lost. The battery must be replaced to make the synthesizer useful again. The following describes the process for replacing the battery.

(Click any picture for more detail.)

Here is the telltale sign that the battery is dead. When you power up the module, it displays "Prog I00 Init Prog", meaning that internal program 00 has been reinitialized to nothing and is now named "Init Prog". All 100 internal programs are the same. And to make it obvious, line two reads "Battery Low (Internal)".
Fortunately, it's pretty easy to replace the battery yourself. You just need a Philips screwdriver and a new CR2032 battery, which you can pick up for a few bucks at any electronics store such as Radio Shack. You will also need to reload the factory programs, which I'll describe below.
The first thing you need to do is remove the cover of the M1R. To do this, first unplug everything and take the M1R out of the rack if it's in one. There are two small screws at the top edge of the rear of the case; you need to back these out about 1/8 inch, but you don't need to remove them. Next, remove the five screws on each side of the case; there are three holding on the rack ear, and two more on the side. See the five blue arrows in this picture on the visible side, plus the two showing the location of the screws on the back. Once the side screws are removed and the rear screws loosened, you can slide the cover (top and sides) back about 1/8 inch so it clears the front bezel, and then lift it up. You may need to pull the sides out slightly since they have a small lip that wraps around the bottom.

This photo is looking straight down into the M1R with the cover off.

The usual warnings about static electicity discharge apply. Take precautions so that you don't damage anything.

The arrow indicates the location of the battery. It is held in a little spring-loaded slot. To remove it, simply slide it back against the spring, and pull it out. Put the new battery in.

After replacing the battery, but before putting everything back, power up the M1R for a moment and make sure the "Battery Low" message is gone. It should now look like this:
OK, you're almost done. Unfortunately, with the dead battery you have also lost the internal programs, so you have 100 programs that all sound like a square wave. You need to restore the programs. First I will walk through the setup menus to enable a MIDI System Exclusive program dump, so that the M1R will allow you to transfer the programs from your computer. Until you do this, the M1R has sys-ex messages disabled, so it won't accept a program dump.
Press "Global". You should see the Master Tune screen.
Press "5". You should see the MIDI GLOBAL screen.
Press "+ Page". You should see the MIDI FILTERING screen.
Press "H". The cursor should move to the "EXCL" setting, which is currently "DIS", meaning disabled, and the sub-label on the top row should say "Exclusive".
Press "UP" to change the setting to enabled. It should say "EXCL:ENA".

Finally, send the sys-ex dump of the original program data from your computer to the M1R.

A good, simple, free sys-ex librarian for Mac OS X can be found here: Snoize SysEx Librarian

If you don't have the original factory program data saved, you can get it here: M1 Source Sounds

Open the factory programs with the sys-ex utility and send it to the M1R. While the M1R is receiving the data, the red MIDI activity indicator will be lit.

When the transfer is done, press "PROG" to go back to the main program selection screen. You should see that program 00 has been restored to the factory "Universe" patch. If you press "UP" button you can scroll through the other factory programs. You're all done!