• Code: E736-0000
• Description: Communication error with CCU/modem
• Causes: Communication error with CCU/modem, NCU PCB type error
• Remedy: 1. Install the set of the controller firmware. 2. Replace the NCU PCB. 3. Replace the Main Controller PCB.

• Code: E736-0001
• Description: Error in ROM for backing up fax data
• Causes: An error occurred in ROM for backing up fax data
• Remedy: 1. Install the set of the controller firmware. 2. Replace the NCU PCB. 3. Replace the Main Controller PCB.

• Code: E744-4000
• Description: Engine ID error
• Causes: Invalid engine connection was detected.
• Remedy: 1. Turn OFF and then ON the main power. 2. Check the Engine Controller PCB. 3. Install the Engine Controller PCB. 4. Install the set of the controller firmware. 5. Check the model code. (When the model code and the engine code are mismatched, E744-4000 occurs.)

• Code: E744-5000
• Description: Error in the Control Panel PCB
• Causes: Error in the Control Panel PCB (microcomputer)
• Remedy: 1. Check the Control Panel PCB, and install the firmware (PANEL). 2. Install the set of the controller firmware. 3. Replace the Main Controller PCB.

• Code: E744-6000
• Description: Communication error with Wireless LAN PCB
• Causes: Communication with the Wireless LAN PCB could not be established.
• Remedy: 1. Turn OFF and then ON the main power. 2. Check the connection of the Wireless LAN PCB. 3. Install the set of the controller firmware. 4. Replace the Wireless LAN PCB. 5. Replace the Main Controller PCB.

• Code: E804-0004
• Description: Controller Fan error
• Causes: Since the startup of the Controller Fan, the Fan was locked for a specified consecutive period of time.
• Remedy: 1. Check power supply to the Controller Fan. 2. Replace the Controller Fan.

• Code: E805-0000
• Description: Main Fan error
• Causes: The Main Fan was locked for a specified consecutive period of time.
• Remedy: 1. Check the connection of the Main Fan. 2. Replace the Main Fan.

• Code: E808-0000
• Description: Low-voltage power supply failure detection
• Causes: Printer detected low-voltage power supply failure.
• Remedy: 1. Replace the Engine Controller PCB.