Kyocera TASKalfa 7002i Service Manual page 1342

F040: Communication error between the main unit and CPU (Communication error
between the controller and the print engine)
The communication between the main PWB and the engine PWB is faulty.
Step Check description
1 Resetting the main power
2 Checking the connection
3 Replacing the main PWB
4 Replacing the engine PWB The engine PWB is faulty.
5 Replacing the LVU
Assumed cause
The communication
between the controller and
the print engine is faulty.
The connectors are not
properly connected or the
wire is faulty.
The main PWB is faulty.
The power from the LVU is
not supplied to the engine
PWB.
7-482
Measures
Remove the original and
check the sensor. Next, turn
off the power switch and main
switch. Then, turn on the
main switch and power
switch when passing 5 sec-
onds.
Clean the terminal of the fol-
lowing wire connectors and
reconnect the connectors. If
there is no continuity, replace
the wire. • Engine PWB
(YC5) - Main PWB (YC63) •
Engine PWB (YC41) - LVU
(YC6, 8)
Replace the main PWB.
Replace the engine PWB.
If 5V or 24V is not generated
from the LVU, replace the
LVU.
2WA/2NJ/2RK
Reference
Wiring dia-
gram
Detaching
and Reat-
taching the
main PWB
Detaching
and Reat-
taching the
engine
PWB
Detaching
and Reat-
taching the
LVU