had a bad load weighing circuit on cop2 board, i borrowed a board from a friend to get the car running while our board was out for repair. Here is the problem, the borrowed board works fine, load set up nice, car runs great, the problem was that the top 10 floors would not light the car calls, bottom 10 floors would light, the car would go to the floors, but would not light the call light. ok so I'm thinking no problem, when we get our board back the problem should be solved. so we get our board back, load weighing works fine, car works fine, however now only the top 2 floors will not light the car light, car accepts call and will go to floor, but no light. now I'm thinking bad connections? redo all ribbon cables, same outcome. just to be sure i installed first board, and again car runs fine, but no lights on the upper 10 floors, put my original board back in, and now only top 2 will not light. talked to an otis guy and he thinks it may be something to do with the U12 chip, believe it is an eprom or eeprom any ideas