• Code: U14 ... U17
• Description: Tray [2] [3] [4] [5] Interface Failure U14: Tray 2 U13: Tray 3 U16: Tray 4 U17: Tray 5
• Remedy: 1 Cycle power to the printer. Does the error still appear? Go to step [2]. Complete 2 Check each of the lower tray connectors between the LTA Controller Board(s) and the Engine Controller Board. Is there continuity between the wiring harness? Replace in the following order: LTA Controller Board Engine Controller Board Replace the problem wiring harness or connector.

• Code: U18 ... U21
• Description: [Yellow] [Magenta] [Cyan] [Black] LED Failure U18: Yellow U19: Magenta U20: Cyan U21: Black
• Remedy: 1 Cycle power to the printer. Does the error still appear? Go to step [2]. Complete 2 Try to isolate the problem LED Head by swapping with another LED Head. Does the error move with the LED Head? Replace the LED Head. Go to step [3]. 3 Ensure the wiring harness to the LED Head is properly connected and not damaged, misaligned or crimped. Is the wiring harness defective? Reconnect or replace wiring harness. Go to step [4]. 4 Check continuity between the Toner Sensor Board and the Engine Controller Board. Is there continuity? Replace the Engine Controller Board. Replace the Toner Sensor Board and/or Wiring Harness.

• Code: U26 ... U29
• Description: [Yellow] [Magenta] [Cyan] [Black] Imaging Unit Failure U26: Yellow U27: Magenta U28: Cyan U29: Black
• Remedy: 1 Is the Imaging Unit installed and seated properly? Go to step [2]. Reseat the imaging unit. 2 Visually inspect the Imaging Unit Drum Contact Assembly and springs. Are the contacts damaged or dirty? Replace the IU Drum Contact Assembly. Go to step [3]. 3 Use service diagnostics to test the CMYK IU Sensor. Does the sensor function correctly? Go to step [6} Go to step [4]. 4 Verify continuity between the IU Sensor Board and the Engine Controller Board at the JODEN connector. Y pin 9 to pin 12 M pin 1 to pin 3 C pin 5 to pin 6 K pin 10 to pin 13 Replace the Engine Controller Board. Go to step [5]. 5 Check the wiring harness. Is the wiring harness defective? Replace the wiring harness Replace the Back Plate Assembly. 6 Use service diagnostics to check the IU Up/Down motor. Is the Transfer Unit functioning properly by lifting the Imaging Unit? Go to step [11]. Go to step [7]. 7 Visually inspect the Transfer Unit gears and lifting arm. See “Transfer Unit Arm and Gear Up/Down Movement of the Imaging Units” on page 8-232. The gears should lift the arm when rotated in one direction and stop rotating. Does the gear stop rotating when the arm is in the raised position? Go to step [8]. Replace the Transfer Unit. 8 Check the appropriate fuse on the Engine Controller Board to see if it is blown. Cyan = F5 Magenta = F2 Yellow = F3 Black = F4 Go to step [10]. Go to step [9]. 9 Verify the Low Voltage Power Supply to the POWER connector on the Engine Controller Board is supplying +34 volts to pins 12, 13, and 14. Replace the Imaging Unit Motor. Replace the Low Voltage Power Supply and/or wiring harness. 10 Check the Imaging Unit wiring harness. Is the wiring harness defective? Replace the wiring harness. Replace the Engine Controller Board. 11 Inspect the Printer Unit Chassis for warping or damage. Replace the Printer Unit Chassis. Replace the Engine Controller Board.

• Code: U30, U31
• Description: U30: Flash Hardware Failure U31: Flash Software Failure
• Remedy: 1 Cycle power to the printer. Does the error reappear? Replace the Engine Controller Board. Complete

• Code: U32
• Description: Fuser Fan Failure
• Remedy: 2 Verify +34 volts is being supplied to fuse F7 on the Engine Controller Board. Is there +34 volts? Replace the defective fan and wiring harness. Go to step [2]. 3 Verify +34 volts is being supplied to fuse F7 on the Engine Controller Board. Is there +34 volts? Replace the defective fan and wiring harness. Go to step [3]. 4 Verify the Low Voltage Power Supply to the POWER connector on the Engine Controller Board is supplying +34 volts to pins 12, 13, and 14. Replace the Engine Controller Board. Replace the Low Voltage Power Supply and/or wiring harness.

• Code: U33
• Description: Fuser 110v/220v Mismatch Failure
• Remedy: 1 Ensure the proper Fuser (110v vs. 220v) is installed in the printer. Is the correct Fuser installed? Replace the Engine Controller Board. Have the customer replace the Fuser Unit.

• Code: U34
• Description: Unsupported Duplex Unit ROM Failure
• Remedy: 1 Verify the correct Phaser 7300 Duplex Unit is installed. Go to step [2]. Replace the Duplex Unit. 2 Check that the Duplex Unit is correctly installed and fully seated. Replace in the following order: Duplex Unit. Engine Controller Board. Reseat the Duplex Unit

• Code: U35 ... U38
• Description: Unsupported Tray [2] [3] [4] [5] ROM Failure U35: Tray 2 U36: Tray 3 U37: Tray 4 U38: Tray 5
• Remedy: 1 Verify the correct Phaser 7300 LTA or LTD is installed. Replace in the following order: LTA Controller Board Engine Controller Board Replace the tray.