My M-audio keystation 61 midi keyboard stopped working and the culprit is on microcontroller which is responsible, among other things for usb connection. That chip costs 1$ but I’ve been told that the original code is protected and can’t be find and the whole original pcb replacement is to costly. The whole circuitry is very simple: there are 2 chips, first one (W78E052DDG) is connected to all of the keys matrix and their velocity calc (24 input pins). Then the result is sent to another chip (micro controller C8051F320) via 14 pin jack, which is doing USB/midi communication.
It should be fairly easy to replace second pcb with arduino considering that it gets sorted out signal from keyboard velocity chip? Right?
Or maybe to replace both chips and connect 24 pins matrix directly to arduino?