I decided to have one more look at the data pins, largely inspired by this oscilloscope trace from part 3. I figured if the address and select pins were working (yellow, cyan and purple) what could I do to try to work out what is driving the data pins (darker blue) wobbly... And no, after … Continue reading Diagnosing and attempting to fix a Yamaha DX100 – Part 4 →

At the end of part 1, I've established that the basics all seem ok (PCB, interconnections, power) and that basic digital logic stuff is happening. In part 2 I checked the ROM, reflowed a number of the solder joints, and started to look at the connectors between the main PCB and the LCD, but still with … Continue reading Diagnosing and attempting to fix a Yamaha DX100 – Part 3 →