Just an update to friends and commenters. The other day, Synthiq said:
After recapping the power supply and replacing the voltage regulators, I managed to restore power. I replaced the buffer. I have no sound and will begin troubleshooting, but on the SCI Max, there are LEDs for each of the six voices. Most of the keys provoke the LEDs, but not all. More to come.In the schematic I found, the CD4503 buffers are part of the keyboard and button scanning circuit so if one input is disconnected there should be some keys that wouldn't work. Only 4 of the 6 buffers in each package are used so I guess there is a possibility that the signal is routed through one of the unused buffers with inputs at pin 12 or 14 instead but then pin 7 has to be disconnected as well.
Statistics: Posted by Apostle — Fri Jan 31, 2025 11:49 pm