I was working on the Autocheck system of my '92 100S last week and I must have caused a problem with the Tachometer. If I remove the instrument cluster daughter board, the tach works fine. With it installed the tach needle may jump a few times and then stops at the bottom. I did fix the autocheck display though. I had to resolder some of the connections on the daughter board. Does anyone have an idea what the problem may be or know of a source for the schematic for the instrument cluster? I have the complete wiring diagram for the car, however, it does not include the IC schematic.