Kyocera TASKalfa 7002i Service Manual page 1256

Step Check description
3 Replacing the engine PWB The engine PWB is faulty.
C3900: Scanner backup memory read / write error (Engine EEPOM)
The read-back value of the engine EEPROM differs.
Step Check description
1 Resetting the main power
2 Checking the EEPROM on
the engine PWB
3 Checking the EEPROM on
the engine PWB
4 Replacing the engine PWB The engine PWB is faulty.
C4001: Polygon motor synchronization error
The ready signal is not at the L level when passing 30s after the polygon motor drive starts.
Step Check description
1 Checking the connection
2 Checking the polygon
motor
3 Firmware upgrade
Assumed cause
Assumed cause
The EEPROM on the
engine PWB does not
operate properly.
The EEPROM is not prop-
erly installed.
The EEPROM is faulty.
Assumed cause
The connector is not prop-
erly connected. Or, the
wire is faulty.
The polygon motor does
not rotate properly.
The firmware is not the lat-
est version.
7-396
Measures
Replace the engine PWB.
Measures
Turn the power switch and
the main power switch off .
After 5s passes, turn the
main power switch and the
power switch on.
Reattach the EEPROM on
the engine PWB.
Replace the EEPROM on the
engine PWB and execute
U004.
Replace the engine PWB.
Measures
Clean the terminal of the fol-
lowing wire connectors and
reconnect the connectors. If
there is no continuity, replace
the wire. • Polygon motor -
Engine PWB
Check the rotation sound of
the polygon motor, and reat-
tach or replace the LSU if it
does not rotate properly.
Upgrade the engine firmware
to the latest version
2WA/2NJ/2RK
Reference
Detaching
and reat-
taching the
engine
PWB
Reference
Detaching
and reat-
taching the
EEPROM
Detaching
and reat-
taching the
EEPROM
Detaching
and reat-
taching the
engine
PWB
Reference
Wiring dia-
gram
Detaching
and reat-
taching the
LSU
Firmware
Update