SuperJX Maintenance

Maintenance page dedicated to getting you to the information you need quickly when your SuperJX stops working properly or is reported as being “dead”.

There are a huge number of pages showing how to maintain the SuperJX, please use the main menu to access the full content.

Power Supply Repair & Upgrade

Sort out the problems with the JX10 or MKS70 power supply, same techniques can be used on the JX8P and many other instruments.

This covers apacitor replacement, resistor upgrades, transistor change, dry joint repair and the components necessary to fix it all!

SuperJX Power Supply


Transformer Tapping Change

Change your UK, Japanese, USA or European specification SuperJX into a different voltage supply using this guide. Contains important information about the earthing for the UK and change of input connector.

SuperJX Mains Input Configuration


Keyboard Refurbishment

Two guides showing how to fully refurbish a JX10 keyboard assembly.


Removing MKS70 Main & Voice Boards

Teardown of the Roland MKS70 and how to take it apart carefully without damage to do repairs and upgrades. Essential guide for upgrading firmware without damaging your SuperJX Roland MKS70.

MKS70 Board Removal

MKSDismantle- (17)

JX10 Encoder Replacement

A guide showing how to replace the JX10 encoder with a low cost but reliable modern one from Bourns. Note that this uses an encoder that has fewer pulses per revolution but still has satisfactory performance and you don’t need to try and hunt down a used 30 year old encoder that wont last. In principle, the MKS70 can take the same encoder but no detailed instructions have been trialled yet.

Roland SuperJX Encoder Replacement


MKS70 Replacement Switches

An easy step by step guide to replacing the switches on the Roland MKS70 in the most efficient way possible.

MKS70 Replacement Switches


MKS70 Noise Reduction

A fabulous modification that routes internal wiring differently on the MKS70 to reduce noise considerably. A full explanation of why it works too!

Roland MKS70 Noise Reduction


JX10 Cartridge Cable

The cartridge cable is in a vulnerable position on the JX10 and can fail if opening regularly or if it was manufactured with it trapped in the hinged part of the casing. this guide shows how a simple PCB and cable modification can put this right and allow the use of the Roland cartridges or the Vecoven 16 bank M1024C cartridge.

JX10 Replacement Cartridge Cable


JX10 Flat Cartridge Flat Cable

JX10 Display Board Flat Cables

Two pages showing how to replace the flat cables that connect to the Display Board:

SuperJX Display Issues

A description showing the failure modes of the SuperJX Vacuum Fluorescent Display, also mostly applicable for other synths with ancient VFD modules.

Some descriptions present ideas of how issues can be fixed by skilled technicians and hobbyists.

Super JX Display Failure Modes


Vecoven Wired PWM Kit Fitting

An explanation of how to tackle the fitting of the Vecoven PWM kit to the JX10 or MKS70.

Vecoven PWM Kit Fitting

Copyright © 2022 Super Synth Projects, Guy Wilkinson