MKS-50 ZONE
MKS-50 ZONE
Battery DamageNote: These parts and procedures also apply to replacing a battery on the Alpha Juno‑1, Alpha Juno‑2, SynthPlus 10 and SynthPlus 80

Well...... I finally replaced the internal lithium battery in my MKS‑50. I've owned my MKS‑50 for a looooong time and I've never had to replace the battery...... for 27+ years. I thought I would stay one step ahead of the game and replace the battery now before it leaks and causes any circuit board damage. I decided to install a battery holder at the same time so that future battery replacements will be easier. So...... the next replacement time will be when? The year 2042? I should mention that this is not a project for a novice. If you have little or no experience using a soldering iron, this is a really bad time to start learning. I recommend that you take your keyboard to a Roland Authorized Service Center


PARTS
I buy all of my coin cell batteries from mouser.com
The battery is a CR2032 Lithium Battery (Mouser Part Number: 658‑CR2032)
The battery holder is a Through-Hole PCB Mount (Mouser Part Number: 534‑1026)

I recommend buying a name‑brand battery like Panasonic. Saving fifty cents to purchase an off‑brand is, in my opinion, a bad idea. This battery is going to last a very long time so get a quality one without the need to worry about a cheap‑o brand leaking and ruining your circuit board


PROCEDURE
Before you start, make sure you have saved all of your patches and tones to an external device like your computer.
* * * All of the internal patches and tones will be erased when the old battery is removed! * * *

Make sure you are wearing eye protection, are properly grounded and working on a static-free workbench or table.
* * * Please don't ignore the advice of eye protection, grounding and a static-free area * * *
The chances of finding new circuit boards or a new eye...... slim to none .)

The replacement took me about 45 minutes from start to finish. I was taking extra time and being extremely careful to avoid any ESD nightmares

(Refer to the images below)

1) Unplug the synthesizer!

2) MKS-50 - Turn the module upside-down and remove (8) screws from the bottom cover
    Alpha Juno-1 / Alpha Juno-2 - Turn module upside-down and remove (13) screws from bottom case (leave rubber feet on)

3) MKS-50 - Turn the module right-side up and remove (6) screws from the the rack holders on the sides
    Alpha Juno-1 / Alpha Juno-2 - Hold keyboard chassis and plastic casing in place then carefully turn the keyboard right‑side up

4) MKS-50 - Slide the top cover off
    Alpha Juno-1 - Remove (4) screws from the upper portion of the back case. Slowly and carefully, lift up the top plastic casing
    Alpha Juno-2 - Remove (8) screws from the lower portion of the back case. Slowly and carefully, lift up the top plastic casing

5) MKS-50 - Unscrew the Main PCB from the bottom cover
    Alpha Juno-1 / Alpha Juno-2 - Remove (3) screws from the Main PCB and unplug (3) cable connectors on the right side
                  Make special note of all the connector locations for reassembly
                  ! ! ! Use extreme caution during this next step ! ! ! Here's An lmage Showing Why
                  ! ! ! Some people have cracked their Main PCB beyond repair ! ! !

                  Unplug the 2-conductor ribbon cable from the Chorus PCB and slide the keyboard chassis out of the keyboard case

6) Once you locate the battery on the Main PCB, you will notice it is soldered into place
NOTE: DO NOT UNSOLDER THE BATTERY. THERE IS ALWAYS AN EXPLOSION RISK!
To remove battery, use a small pair of wire cutters and carefully cut the battery leads from the circuit board. Discard the battery.

7) After cutting the battery leads off, unsolder the leads left behind and remove all excess solder from the holes on the circuit board. Ensure the holes are large enough for the new leads on the battery holder

8) Solder the new battery holder in place, insert a new CR2032 battery and re-assemble the case

9) Because the battery was removed, you will need to use a "Special Power-Up Sequence" *

     MKS-50
        1) Press and hold down the [ PATCH A↔B ] + [ DATA TRANSFER ] buttons while turning the POWER button ON.
           The LCD shows RAM check OK !!
           (This clears the old CHECK BATTERY!!! message and tests the RAM. Any errors will display RAM wr/rd ERR !!)

       2) Power OFF the synth then press and hold down the [ 4 ] and [ 8 ] buttons while turning the POWER button ON.
           The LCD shows FACTORY PRESET
           (This intitalizes the synth into POLY MODE)


     Alpha Juno-1 / Alpha Juno-2
        With the Alpha Juno turned ON, Set the MEMORY PROTECT SWITCH on the back of the keyboard to the OFF position
        Turn the Alpha Juno OFF
        Press and hold down the [ KEY TRANSPOSE ] and [ PORTAMENTO ] buttons while turning the POWER button ON
           The display will briefly show [ Copy Prest → Memry ]

     SynthPlus 10 / SynthPlus 80
        With the HS-10 or HS-80 turned ON, Set the MEMORY PROTECT SWITCH on the back of the keyboard to the OFF position
        Turn the HS-10 or HS-80 OFF
        Press and hold down the [ KEY TRANSPOSE ] and [ BRILLIANCE ] buttons while turning the POWER button ON
        The display will briefly show [ Copy Prest → Memry ]


FINALIZING

The "Factory Fresh" setting will be complete after you reload a Tone bank into the User Memory ROM.

SUPER JX ZONE To resume normal operation, power OFF the synth and then power ON

Note: If you continue to see a 'Check Battery!!' error message after following all the steps shown above, see the section on the INFO Page for Initializing RAM


For an MKS-50, the "Special Power-Up Sequence" *
     Copies data from ROM IC7 to RAM IC8
     Tune/MIDI functions are restored
     64 Tones are copied into the Tone 'a Group' (This is the same Tone bank *.SYX file as FACTORYA.SYX)
     128 Patches are copied into the Patch 'A + B Groups'
     16 Chord Memories are restored
     All Tone names in the Tone 'a Group' are copied to the 'A Group" Patch names

     This still leaves the Tone 'b Group' in a state of limbo. If you notice, everything looks good except when trying to call up a Tone
     from the 'b Group'. It just displays a bunch of garbage characters. Simply load one of your Tone *.SYX files and it's
     corresponding Patch *.SYX file back into the 'b Group' and everything will return to normal


For Alpha Juno-1 and SynthPlus 10, the "Special Power-Up Sequence" *
     Copies data from ROM IC10 to RAM IC11
     Tune/MIDI functions are restored
     Chord Memory is restored
     64 Tones are copied from the "Preset Bank' to the "Memory Bank' (This is the same Tone bank *.SYX file as FACTORYA.SYX)


For Alpha Juno-2 and SynthPlus 80, the"Special Power-Up Sequence" *
     Copies data from ROM IC24 to RAM IC25
     Tune/MIDI functions are restored
     Chord Memory is restored
     64 Tones are copied from the "Preset Bank' to the "Memory Bank' (This is the same Tone bank *.SYX file as FACTORYA.SYX)


I think it's amazing the old battery lasted for 27+ years without leaking or showing errors on the display panel. Dodged a bullet!


MKS-50 Cover Removal
Remove (8) screws from bottom case and (6) screws from rack holders and then slide the top cover off

MKS-50 Cover Removal
MKS-50 Battery Location

Alpha Juno-2 Main PCB And Battery Location

Alpha Juno-2 PCB2

Alpha Juno-2 Cover

Alpha Juno-2 PCB


Alpha Juno-1 Battery Location

Note: I own an Alpha Juno‑2 but not the Alpha Juno‑1. Before removing the keyboard assembly, you may want to double check to see if the Alpha Juno‑1 has the same dangers during disassembly as noted here

Alpha Juno-1 Cover

Alpha Juno-1 PCB Macro 1

[ Photo provided by aciddose 2015 xhip.net ]


Safety Precautions and Disclaimer:
Modifications made to any factory stock equipment will always pose an element of risk. Sometimes mistakes are made which are irreversible. Improper soldering and handling of electricity can cause serious injury and damage the synthesizer. Use caution when handling static sensitive devices and the PCB. Make sure you are properly grounded, working on a static-free workbench or table and wearing eye protection during any soldering tasks. The author is not responsible for any damage or injury resulting from this DIY info. Use this DIY information at your own risk. And, I can't stress enough, the importance of wearing eye protection while soldering. That stuff flies everywhere sometimes!




MKS-50 ZONE

info@super-jx.com
Comments/Questions?