Alesis MMT-8
This is another sequencer of this kind in my workshop. This unit had the issue that the LCD display did not always initialize correctly, sometimes showing so-called “garbage characters,” even though the device itself appeared to function properly (it responded logically to control panel operation).
Initially, I suspected failure of one of the 74HC family ICs responsible for communication between the 80C31 processor and the display, but it ultimately turned out that the display itself had failed due to component aging and required replacement with a new compatible model. This required a small modification of the original contrast circuit, as well as modification (in fact replacement) of the connection ribbon cable linking the display to the main board. Finally, I thoroughly cleaned the device housing using a professional ultrasonic cleaner and replaced several key electrolytic capacitors due to the advanced age of the device.
