I came across some old LCD displays which wasn’t equipped with a display controller but only the LCD driver circuits. The label on the display read ‘LMG7410PLFC-A’ but I only got a hit matching ‘LMG7400PLFC’. This is the display which has the controller chip on and that datasheet are quite firm on the fact that one should not use CN3 for connections. Being the only connector with pins soldered to it, I figured that the display might be working without the controller parts.
First thing was to figure out the pinout. From the datasheets of the drivers (LC7940N and LC7942N) and probing around on the board the following pinout is found:
|3||Display_off (Active low)|
|9||VEE (-15) - currently working fine with -10V|
|10||V0 (Tied to pin 8)|