• Code: 79:YZ
• Description: Assertion (uncontrolled FW error)
  Generic Firmware error.
• Remedy: • Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer. • Check that the Printer has the latest Firmware version. If not, update the Firmware to the latest version.

• Code: 81.1:YZ
• Description: Media advance
  Problem finding the Drive Roller zero.
• Remedy: • Open the Window and check for any visible obstacles restricting the movement of the Drive Roller. If there is a wrinkled mass of media 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. • If the printer has a 44 inch scan axis (and a Rewinder), perform the Rewinder diagnostic test to troubleshoot the problem further . Page 4- 34. • Check the connections on the Main PCA; the Media Advance Drive is connected to the connector labeled Paper Motor. • If the System Error continues, replace the Media Advance Driver.

• Code: 81:YZ
• Description: Media advance
  Problem with paper advance.
• Remedy: • Open the Window and check for any visible obstacles restricting the movement of the Drive Roller. If there is a wrinkled mass of media 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. • If the printer has a 44 inch scan axis (and a Rewinder), perform the Rewinder diagnostic test to troubleshoot the problem further . Page 4- 34. • Check the connections on the Main PCA; the Media Advance Drive is connected to the connector labeled Paper Motor. • If the System Error continues, replace the Media Advance Driver.

• Code: 84:YZ
• Description: Roll Feed
  Back tension servo shutdown (roll feeding).
• Remedy: • Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer. • If the problem persists, contact HP support.

• Code: 85:YZ
• Description: Media-axis encoder reading
  Problem finding the Drive Roller zero.
• Remedy: • Perform the Media Drive diagnostic test to troubleshoot the problem further. • If the System Error continues, replace the Encoder Disk and Encoder Sensor.

• Code: 86:YZ
• Description: Carriage Movement
  Possible Paper Jam.
• Remedy: • Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer. • Open the Window and check for any visible obstacles restricting the movement of the Drive Roller. If there is a wrinkled mass of media inside the paper path, lift the Pinch wheels (using the Media Lever) and clear the obstruction.

• Code: 87:YZ
• Description: Scan-axis encoder reading
  Problem finding the Scan-axis encoder reading.
• Remedy: • Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer. • Movement jam. • Possible paper jam. • Mechanical Initiator scan axis measure error. • Check that the Scan-Axis Motor is correctly connected. • Check that the Encoder Sensor is correctly connected. • Remove the Encoder Strip and clean it. • Perform the Scan Axis diagnostic test to troubleshoot the problem further

• Code: 93:YZ
• Description: Ink Pumping
  Unable to pressurize the Ink Delivery System.
• Remedy: • Switch the Power OFF from the back of the Printer and disconnect the Power cord. Reconnect the power cord and power On the Printer. • Perform the Ink Delivery System diagnostic test to further troubleshoot the problem. • If the problem persists, contact HP support.