I donât think this can be connected with keyboard mechanics, when all keys trigger some sound. More probably thereâs something wrong with key decoders TC40H138 (IC1 and IC2), or sub CPU 6805S (IC13)⊠if not the worse case that EGS YM21290 (IC29) or OPS YM21280 (IC36) are illâŠ
Randomly means any key can cause it? That number of key presses is 8 to 15, so number of presses before the problem occurs is changed also randomly?
Does it occur with any sound? With any setting of EG on each operator? Also on initialized sound?
Is affected also something different, for example switches or other controllers behavior?
Have you tried diagnostics?
Could you try to set a basic sound with algorithm 32, set level of all operators to 99, and try by selecting only one operator in time if it occurs on all operators or only on specific operator? Probably it will not diagnose the problem which is not operator specific but voice specific but I would try it as wellâŠ
The best way would be to check also clock (Xtals) and other digital signals - communication between keyboard decoders, sub CPU, MPU, EGS, OPS⊠Task for a specialist.
Daniel Forro
Post by Martin Tarenskeen ***@zonnet.nl [YamahaDX]Post by ***@yahoo.com [YamahaDX]I have a DX7 MK1 that randomly distorts the sound of a note (sounds like an
electronic fire shot) every 8-15 notes. Any note can be affected by this. I
replaced the DAC chip but this did not fix the issue. Has anyone encountered
this problem before and was able to resolve it? Any ideas of probable cause?
Could it be a keyboard issue? Cleaning the keyboard contacts might help?
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MT