Specifications

Chapter 6: FRU Replacement and Fault Isolation Procedures
6-55
6.3.9 MBF Sensor failure
NOTES:
a. The diagnostic tool is not used in this FIP
b. The control panel message may be: Tray Empty
c. This FIP may also fix a bad cassette spring.
d. Try another cassette tray first
1. INITIAL ANALYSIS
Inspect the following components. Are they compatible with your printer version, correctly
installed, not damaged, deformed, or contaminated?
MBF Sensor MCU PWB
LVPS Assembly Sensor Harness Assembly
Inspect the printer paper path. Is it clear of foreign matter, such as staples, paper clips, and
paper scraps?
Yes No
Go to Step 2. Replace the problem components.
2. LVPS ASSEMBLY ANALYSIS
Disconnect P/J 111 from the HVPS. Perform this test within 30 seconds after switching power on.
After 30 seconds, the LVPS shuts down with a no-load condition.
Is there +1VDC between P16–8 and P16–7 on the MCU PWB?
Yes No
Go to Step 3. Go to Section 6.3.1 LVPS Assembly Failure (+5VDC).
3. MBF SENSOR ACTUATOR SIGNAL ANALYSIS
Disconnect P/J 111 from the HVPS. Perform this test within 30 seconds after switching power on.
After 30 seconds, the LVPS shuts down with a no-load condition.
Is there +5VDC between P16–9 and 16–8 on the MCU PWB?
Yes No
Go to Step 4. Replace the MCU PWB.
4. MBF SENSOR SIGNAL ANALYSIS
Disconnect P/J 111 from the HVPS. Perform this test within 30 seconds after switching power on.
After 30 seconds, the LVPS shuts down with a no-load condition.
Is there +5VDC between P/J 16–9 and P/J 16–8 on the MCU PWB?
Open the Front Feeder Cover. Actuate the MBF Sensor.
Is there 0VDC between P/J 16–9 and P/J16–8 on the MCU PWB?
Yes No
Replace the MCU PWB. Go to Step 5