Error code 85

If the display of a TCN vending machine shows the error code 85, in most cases this points to a defect in the slot driver mainboard. This component is central for controlling the individual product dispensing compartments. It makes sure the motors of the respective slots are controlled correctly and the products are dispensed reliably.

[Photo 1: Close-up slot driver mainboard]

What exactly does error 85 mean?

Error code 85 indicates that the machine is not receiving any feedback from the slot driver mainboard or that communication between the main controller and the slot module is interrupted. Typical signs are:

• individual compartments no longer respond,

• product dispensing suddenly stops,

• or the machine doesn’t start up properly.

In practice, the cause is almost always a defective slot driver board or contact problems in the plug connections.

Step-by-step troubleshooting guide

1. Switch off the machines and disconnect the power.
   Safety first – always disconnect from the power supply first.

2. Carry out a visual inspection.
   Check whether there are any visible damages, burnt components, or loose plugs on the slot driver board.

3. Check cables and plug connections.
   Check all cables between the mainboard and the slot board to make sure they are seated firmly.

4. Connect a different board for testing.
   If available, you can temporarily use a working board to narrow down the cause of the error.

5. Replace the defective mainboard.
   In almost all cases, replacing the slot driver mainboard is necessary to get the machine back up and running.

Order the spare part directly

You can find the right replacement mainboard for TCN vending machines with a lift system here:
Slot driver mainboard for vending machines (with lift)

This board is compatible with most TCN models and reliably replaces defective or no longer responsive driver units.

[Photo 2: Product photo of the slot driver mainboard from the shop]

Conclusion

Error 85 on TCN vending machines is a clear sign of a hardware defect in the slot driver mainboard. Software or calibration errors are very rarely the cause.
With targeted diagnostics and replacement of the affected board, the machine can usually be put back into operation quickly.