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- HP Community
- Printers
- DesignJet, Large Format Printers and Digital Press
- T790 - 81:01 error during Initialization

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11-16-2017 01:36 PM
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.
Cheers,
Roy K
11-16-2017 09:03 PM
- 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.

- 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.
- Perform the Media Drive diagnostic test to troubleshoot the problem further.
- Perform the Rewinder diagnostic test to troubleshoot the problem further.
- Check the connections on the Engine PCA; the Media Advance Drive is connected to the connector labeled Paper Motor.
- Adjust the encoder disc and motor mount configuration using the Media Advance Drive installation instructions.
- Replace the Media Advance Drive.
11-17-2017 07:20 AM
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.
Regards,
RoyK
11-27-2017 04:09 PM
Hmm.
"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).