11/34 Console CABLE TWIST

Error: the flat ribbon cable between display/keyboard module and interface module M7859 is twisted.

Detection: the digit display is dead, and all four indicator LEDs are ON.

Explanation: The position of the #1 wire of the flat ribbon cable is documented. But some DEC guys mounted it reverse on both sides, which is electrically the same. So you have to reconnect it exactly as it was before plug off, not as documented.

Repair: plug flat cable in the other way round, you can not damage anything.