Main board: MKS GEN L V1.4
The SD card reader on the original controller LCD (from four years ago, or so) went out, so I replaced it with a touch screen. I found, however, that I don't like the touchscreen interface as much as the LCD home screen, so I ordered what I thought was an identical LCD controller. They certainly look the same.
The original controller is plugged in now and working. It should just be a matter of the EXP1 and EXP2 cables between new and old, but when I plug it in and fire up the printer, the beeper starts a constant, weak beeping, the screen sort of flashes on/off, on/off... Is there something I'm missing? Some fundamental difference between the old LCDs and the new? Is there firmware I'm missing?
EDIT: I saw this post that talks about turning the slots, but they don't move and I'm afraid of applying too much pressure. How hard should it be? Can I accomplish the same thing by reversing the connector on one end of the ribbon cable?