Specifications

Chapter 6: FRU Replacement and Fault Isolation Procedures
6-2
6.2.1 Problem in MCU Nonvolatile RAM: Fault code U6
There is a problem in the nonvolatile ROM.
Notes:
1. Without the diagnostic tool, this FIP is not usable.
2. There is no corresponding control panel message for this item.
3. If the printer cannot be diagnosed further, replace the MCU.
4. If the print engine powers up with a cleaning routine, but the control panel does not display
the normal power-up sequence, try swapping the controller.
1. INITIAL ANALYSIS
Inspect the MCU PWB. Is it compatible with your printer version, correctly installed, not
damaged, deformed, or contaminated?
Yes No
Go to Step 2. Replace the MCU PWB. (If U6 remains, go to Section 6.3.22 Noise )
2. Does fault code U6 appear when you switch ON Main Power?
Yes No
Go to Step 3. Problem corrected.
3. Repeat switching Main Power ON and OFF. Does fault code U6 appear?
Yes No
Go to Step 4. Problem corrected.
4. MCU PWB ANALYSIS. Can you enter Configuration Mode?
Yes No
Go to Step 5. Replace the MCU PWB (If U6 remains, go to Section 6.3.22 Noise ).
5. ROM DATA ANALYSIS. Are the Configuration Mode parameters correct?
Yes No
Replace the MCU PWB (If U6 remains, go to Section 6.3.22 Noise ). Go to Step 6.
6. MCU PWB ANALYSIS
Change the incorrect parameters and switch OFF Main Power.
Does fault code U6 still appear when you switch ON Main Power?
Yes No
Replace the MCU PWB (If U6 remains, go to Section 6.3.22 Noise ). Go to Step 3.