[HP DesignJet T3500 series]

If this error is reported during printer setup, it may indicate that the printer has been dropped during transportation, causing structural damage. Before continuing with the 81:01 troubleshooting, first look for structural damage. To identify the structural damage, look for the following three things:

- Persistent 81:01 error codes
- Platen fingers rubbing on the roller surface, leaving black marks on the roller
- A gap in the platen beam. If there is any gap in the vertical direction between the plastic of the platen and the metal side plate, then the chassis is damaged and the printer cannot be repaired.

If no structural damage, continue with these steps:

1. Check for any visible obstacles restricting the movement of the drive roller. If there is a wrinkled mass of paper inside the paper path, lift the pinchwheels and clear the obstruction.
2. Perform the paper drive diagnostic test to troubleshoot the problem further.

If system error persists:

3. Check the connections on the engine PCA; the paper advance drive is connected to the connector labeled Paper Motor.
4. Adjust the encoder disc and motor mount configuration using the paper advance drive installation instructions.
5. Replace the paper advance drive.