I developed this in order to use a cartridge with the JX10. With a Roland cartridge, it was noticed that patches were becoming corrupted or the cartridge was not recognised. Investigating the issue, it was discovered that the flat cable was damaged.
I really wanted to fix the issue since having invested in the Vecoven M1024C, a huge cartridge that has easy bank selection menu when using Vecoven software upgrade. The big cartridge is useful because with my work on the JX10 it was a pain to have to keep throwing bulk dumps at the instrument. Many JX10 users probably don’t have a cartridge and probably don’t realise that the cartridge port may not work anymore.
The cartridge cable in the JX10 is particularly vulnerable because it passes along the rear panel next to hinges and over the top of sharp metalwork as well as being folded. The effects of ageing affect the bonding around the connector ends and there are some reports of connector strips peeling away and linking to the neighbouring terminal.
The pictures below show common failure modes:
- Detachment of backing strip at connector end
- Kinks and bends caused by trapping
- Damage caused by hinge or fixing screw
When disturbed by maintenance or modifications, the flat cable can become intermittent, leading to patches being corrupted when loaded to and from a cartridge.
If flat cable ends show signs of the backing plastic peeling away then be aware that as soon as it is pulled, it will disintegrate. This is because the glue is no longer holding it together, the connector is instead. A cable like this once removed cannot be put back together.
The picture below show the cartridge cable end backing peeling away. It had been previously removed and put back in such a way that the conductors were biased with force away from the backing plastic such that the glue eventually gives way and dries up.
For the JX10, a transition PCB has been developed to replace this cable with a common 1.27mm pitch IDC cable. The method has been developed to be as easy as possible for the installer and least invasive. The old connectors with 2.50mm spacing can remain in place, drilling of PCBs is avoided and if wanted a similar shielding arrangement is installed. The Assigner Board has plated through holes so damage to them is avoided because the connector remains in place.
This method also ensures that the parallel data/address connections all have the same length and impedance to minimise corruption.
A guide that includes a parts list can be downloaded here: JX10CartFlatCableReplace-V4
More replacement flat cables are planned, particularly for the Display Board to Assigner connections; they will use the same technique but will involve removal of the existing flat cable connector on the Assigner and Display Boards.
The soldered and fitted cable assembly is available as well as a blank PCB.
Copyright © 2017 Super Synth Projects, Guy Wilkinson