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 P/N: 658‑CR2032)
The battery holder is a ThroughHole PCB Mount (Tayda SKU: A‑869)
- Note: For the MKS‑50, a thin profile holder like the Tayda A‑869 is needed. There's not much clearance because of nearby components. Other holders may work on the Alpha Juno and HS synths but I highly recommend the Tayda A‑869
- 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 battery replacement on the MKS‑50 took me about 45 minutes from start to finish. I was taking extra time and being extremely careful to avoid any ESD nightmares. The battery replacement on the Alpha Juno‑2 took considerably longer due to the outer case and PCB removal
(Refer to the images below)
- 1) Unplug the synthesizer!
- 2) MKS‑50 - Remove (8) screws from bottom cover. Turn module right‑side up & remove (6) screws from the rack holders on the sides
Alpha Juno‑1 / HS‑10 - Turn module upside‑down & remove (4) screws from the side & (13) screws from bottom case (leave rubber feet on)
Alpha Juno‑2 - Turn module upside‑down & remove (8) screws from the side & (15) screws from bottom case (leave rubber feet on) br> 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 the Main PCB beyond repair ! ! !
Unplug the 2‑conductor ribbon cable from the Chorus PCB and slide the keyboard chassis out of the keyboard case
- 3) 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.
- 4) 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
- 5) Solder the new battery holder in place, insert a new CR2032 battery and re‑assemble the case
- 6) Because the battery was removed, you will need to use a "Special Power‑Up Sequence" * as follows
- MKS‑50
- Press and hold down the [ PATCH A↔B ] and [ 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 !!
- 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. If MONO MODE is required, hold down the [ 3 ] and [ 7 ] buttons instead)
- Press and hold down the [ PATCH A↔B ] and [ DATA TRANSFER ] buttons while turning the POWER button ON.
- Alpha Juno‑1 / Alpha Juno‑2
- Power ON the synthesizer
- Set the MEMORY PROTECT SWITCH on the back of the keyboard to the OFF position
- Power OFF the synthesizer and wait 30 seconds
- Press and hold the [ PORTAMENTO ] and [ DATA TRANSFER ] buttons and then power ON the synthesizer
- The LCD will briefly display "Initlz Funct ram"
- Turn the Alpha Juno OFF and wait 30 seconds
- 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
- Power ON the synthesizer
- Set the MEMORY PROTECT SWITCH on the back of the keyboard to the OFF position
- Power OFF the synthesizer and wait 30 seconds
- Press and hold the [ PORTAMENTO ] and [ DATA TRANSFER ] buttons and then power ON the synthesizer
- Prepare yourself then very quickly press the [ TUNE / FUNCTION ] button immediately after seeing the message "Initlz Funct ram"
- Turn the synthesizer OFF and wait 30 seconds
Press and hold down the [ KEY TRANSPOSE ] and [ BRILLIANCE ] buttons while turning the POWER button ON
- The display will briefly show [ Copy Prest → Memry ]
- Power ON the synthesizer
The "Factory Fresh" setting will be complete after you reload the Tone bank called FACTORYB.SYX into the User Memory ROM
For the MKS‑50, this additional bank of Tones is accessed via the [ PATCH A↔B ] button
For the Alpha Juno‑1, Alpha Juno‑2, HS‑10 and HS‑80, this additional bank of Tones is accessed via the [ MEMORY ] button
To resume normal operation, power OFF the synth and then power ON
- Note: If you continue to see the "Check Battery!!" error message after following all the steps shown above, check the following
- Did you press the the buttons down hard enough? Over time, the tact switches are less responsive and need to be pressed down firmly
- Before starting any reset procedures, did you set the MEMORY PROTECT SWITCH to the OFF position and then turn the power OFF?
- Verify the new battery is actually a new one, not defective and measures close to 3.0V on a Voltmeter
- 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)
- 28 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" *
- Initializes RAM and resets the "Check Battery!!" error message
- 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)
- Initializes RAM and resets the "Check Battery!!" error message
- For Alpha Juno‑2 and SynthPlus 80, the"Special Power‑Up Sequence" *
- Initializes RAM and resets the "Check Battery!!" error message
- 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)
- Initializes RAM and resets the "Check Battery!!" error message
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
Remove (8) screws from bottom case and (6) screws from rack holders and then slide the top cover off
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
Alpha Juno‑2 Main PCB And Battery Location
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
(Click For Larger Image)
(How To Remove The Alpha Juno-2 Main PCB Without Removing The Keyboard)
Alpha Juno‑1 Battery Location
The Alpha Juno‑1 Main PCB is attached to the underside of the keyboard. Unlike the Alpha Juno‑2, there are no dangers of breaking the PCB during removal. To access the backside of the PCB to unsolder the battery pins, it is best to unplug all of the white plastic cable connectors on the right‑hand side before flipping it over
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
(Click For Larger Image)
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!
The Information On This Page Is Current As Of
