I have an MCE IMC controller that randomly latches calls to the fourth and fifth landings. This occurs with no passengers, even with the controller on test.

These landings are secure. To access these floors, you push your desired floor and then press a sequence of buttons on the COP to latch your call. Before your call latches, your desired floor button flashes (for about 15 seconds) as well as the input LED on the HC-CIO board. When the "phantom" calls latch, there is no flashing, they just latch. On my group computer (not sure what MCE calls it) I checked the secure car call log, these phantom calls do not register as being entered. I can sit in the machine room and watch the calls latch on the screen as well as on the HC-CIO board.

I checked all triacs, zener diodes and resistors on the HC-CIO board, all checked fine. I replaced the board with a brand new board from MCE, no change. I have removed and reseated all ribbon cables. I have a new HP-CIO board and ribbon cables on order.

Any other ideas?