Anyone know if I can use a qs6.2 board in a 6.1?
I don’t think the QS6.2 rear mainboard jacks will align with the openings on the 6.1 housing without modification. Also the board mounting screws may not be located in the same places.
I don’t have a QS6.2 circuit schematic to compare against the 6.1 schematic.
The keyscan chip should work if the keyboards are wired the same.
Power supply and power connector should be similar.
LCD display is same - cable should be wired the same.
Volume control and slider pots look similar. Pushbuttons look similar - different layout.
Thanks so much for the reply. Sounds like you may know a thing or two about the qs6.1. Maybe you can help shed some light on my trials and tribulations? I have been having intermittent failure where the synth freezes up and screen reads “address error” or “invalid instructn” or just garbled text. Turning on and off or reboot (hold 0 and 3 while powering up) will sometimes resolve. However, problem will continue to happen more and more frequent to the point where I cannot get it to stop without taking the synth apart. Poking around, re-seating cables, a little contact cleaner and problem goes away. But, then it always comes back. I have probably taken it apart at least 10 times. I am not ready to give up on this as I love this synth. When having the issues and I run the diagnostic tests, I get failure on the SRAM processor. But, again, it is intermittent. Battery reads proper voltages. Anyway, I thought if i could find a replacement board, i would just go that route. But, really appreciate any comments or ideas you may have. Thanks again!!
Take a really good look at the power supply capacitors for bursting or swelling then look at all the rest of your capacitors. Replace any ( all) suspect caps. Send me a email and I’ll send you the board schematics I downloaded from the internet along with a troubleshooting unofficial manual.ronf57@aol.com
For future reference, try removing (carefully) the EPROM from it’s socket on the main board and reinstalling. Maybe clean the pins with isopropyl alcohol. Over time these pins can oxidize and give poor connections. Reseating the chip will fix. I have fixed a QS synth with this method.
Also, if the backup battery voltage dropped (due to age) in the range of < 2volts, it can permanently damage the SRAM. Replacing the battery will not fix. The 128K x 8 SRAM is still available from Mouser or DigiKey for a few $$. It is surface mount SOIC and can be replaced with some careful soldering. Once replaced and a new battery installed, you will need to use MIDI Sysex files to reinstall the factory patches and settings.