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T790 - 81:01 error during Initialization

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DJ T790

Hi All,

I replaced the Encoder Sensor and Disk for the Paper Drive.

The Frame looks just fine. All cable connections look fine.

The Rewinder Diagnostic test passes.

I adjusted the Transmission using the correct adjustment tool.

I ran other Diagnostics to see if any of them also caused this error.

After replacing the Encoder Sensor I ran the Paper Drive Diagnostics and it passed. Then when initializing the printer the 81:01 error occured. Subsequent Paper Drive tests have failed.

The only other 2 parts I can think of are the Drive Transmission and the Mian PCA.

I am reluctant to replace the Drive Transmission as it appears perfectly functional when it has run.

I am thinking that there are signal issues with the Main PCA.


Please, any input would be appreciated.


Roy K

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Level 13
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System Error: 81:01
Problem Description: Paper axis error—the copier will restart and run a diagnostic test
Corrective action: None.
System Error: 81:YZ
Initial checks: This error can occur because the product has been dropped during transportation, causing structural damage. Before continuing with the 81:YZ troubleshooting, first look for structural damage.
To identify the structural damage, look for the following three things:
  • Consistent 81:YZ error codes.
  • Platen fingers rubbing on the roller surface, leaving black marks on the roller.
  • A gap on the platen beam. If there’s any gap in Z (vertical direction) between the plastic feature of the platen and the metal side plate, then the chassis is damaged and the unit cannot be repaired.
Problem Description: Problem with paper advance. This source of error could come from an error in any of the following systems: paper motor, disk encoder, cables or main electronics.
Corrective action: Try the following:
  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 (using the Media Lever) and clear the obstruction.
  2. Perform the Media Drive diagnostic test to troubleshoot the problem further.
  3. Perform the Rewinder diagnostic test to troubleshoot the problem further.
  4. Check the connections on the Engine PCA; the Media Advance Drive is connected to the connector labeled Paper Motor.
  5. Adjust the encoder disc and motor mount configuration using the Media Advance Drive installation instructions.
  6. Replace the Media Advance Drive.
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Thanks David,

I have this info. 

Via the troubleshooting and having already replaced the Encoder Sensor and Disk, I think the issue comes down to the

Drive Motor or the Main PCA.


In your experience, would you replace the Drive Motor 1st or the Main PCA 1st ?


From a visual stand point there appears to be nothing wrong with the Drive motor and there is no binding or drag that I can feel.




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Level 3
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"Then when initializing the printer the 81:01 error occured. Subsequent Paper Drive tests have failed."

Than Road Runner signals beep-beep (two! not three), right?


Have you checked paper sensor, the one that detects paper inserted from roll (if its stucked or defective).


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