If the MPU is available at all !
I own a DX7mkII too and I´m lucky to have the Yamaha service in my hometown.
I had such a prob w/ my Roland D550,- it recieved MIDI, I could operate it from the fronpanel, the display showed all,- but no tone.
In the end, it was the processor which recieved the MIDI but didn´t transmit info to the tone generator.
The search for the now unavailable processor chip incl. Roland firmware/software (embedded in the chip itself) needed over a year.
The Roland service, also in my hometown, was unable to order the chip in japan,- out of stock ...
Now we found it new at Roland service department in another country.
Soldering out the damaged MPU is easier than getting the new one in without damage of the new chip.
You should have the right tools or contact Yamaha service.
Where are you located ?
Am 23.01.2011 13:01, schrieb hnrgaardmadsen:
All in all, I'm suspicious that it is the MPU that has given in. Does anybody have any experience with this problem? Frankly, I hope it is something else than the MPU, it seems to be quite a job to desolder it and replace it with a new one. Any ideas will be appreciated!
Best regards,
Helge