Had an interesting bit of troubleshooting today. Maybe this will help out someone else down the road with a similar issue.
One of our techs swapped out an FS-539 on a C360i yesterday. Every symptom pointed to a finisher that was completely dead. The LED on the board in the finisher would not light, copier did not know the finisher was even attached. A check of all fuses on the board tested OK. If you just want the solution, jump to the last paragraph...
It was brought back to the office for troubleshooting. I was sure that it was going to be a dead board that I would need to send in for warranty replacement. Ended up spending a total of close to 2 hours trying to figure out what the problem was. I tried the board with all wire harnesses disconnected except the harness coming from the copier. Miraculously the copier saw the "finisher" at that point and the LED on the board was blinking. I installed the board in a known good finisher, and it functioned perfectly.
Put the board back into the original finisher, same as before, acted completely dead. Removed one wire harness at a time from the board until I found the culprit. It was the harness connecting to socket J4. There are 3 motors, 5 Photo Sensors, and one LED (from the manual stapler). Disconnected everything on the other end of the harness and connected one at a time. Eventually found the problem child. I fully expected it to be a motor, but it turned out to be the entrance sensor (PS4). Disconnecting the harness on the side of the finisher (under front cover) and the finisher fired up perfectly.
Found that the short 8" piece of wire harness that connects from the side of the finisher to the entrance sensor was pinched from the factory and shorting out on the metal plate on the entrance to the finisher. That shorted wire took out the entire finisher and made it act like it was completely dead.
One of our techs swapped out an FS-539 on a C360i yesterday. Every symptom pointed to a finisher that was completely dead. The LED on the board in the finisher would not light, copier did not know the finisher was even attached. A check of all fuses on the board tested OK. If you just want the solution, jump to the last paragraph...
It was brought back to the office for troubleshooting. I was sure that it was going to be a dead board that I would need to send in for warranty replacement. Ended up spending a total of close to 2 hours trying to figure out what the problem was. I tried the board with all wire harnesses disconnected except the harness coming from the copier. Miraculously the copier saw the "finisher" at that point and the LED on the board was blinking. I installed the board in a known good finisher, and it functioned perfectly.
Put the board back into the original finisher, same as before, acted completely dead. Removed one wire harness at a time from the board until I found the culprit. It was the harness connecting to socket J4. There are 3 motors, 5 Photo Sensors, and one LED (from the manual stapler). Disconnected everything on the other end of the harness and connected one at a time. Eventually found the problem child. I fully expected it to be a motor, but it turned out to be the entrance sensor (PS4). Disconnecting the harness on the side of the finisher (under front cover) and the finisher fired up perfectly.
Found that the short 8" piece of wire harness that connects from the side of the finisher to the entrance sensor was pinched from the factory and shorting out on the metal plate on the entrance to the finisher. That shorted wire took out the entire finisher and made it act like it was completely dead.
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