Sharp AR-M550N Service Manual page 369

Communication trouble between
Main Sub
Title the MFP control and the scanner
code code
(MFP control detection)
E7 80 Case 1 Trouble
position/
Cause
Remedy
Note
Main Sub MFP control-PCU communication
Title
code code trouble (MFP control detection)
E7 90 Phenomenon Display
Details
Section
Operation
mode
Note
Case 1 Trouble
position/
Cause
Remedy
Note
Defective connection of
the slave unit PWB
connector
Defective harness
between the slave unit
PWB and the MFP
control PWB
Slave unit PWB mother
board connector pin
breakage
Check connection of the
connector between the
slave unit PWB and the
MFP control PWB and
the harness.
Check grounding of the
machine.
Lamp
Message
MFP control-PCU
communication trouble
(MFP control detection)
Communication
establishment error/
framing/ parity/ protocol
error
Follows the
communication protocol
specifications.
Communication error,
timing abnormality of the
communication data and
the communication signal
line
Controller
Defective connection of
the slave unit PWB
connector
Defective harness
between the slave unit
PWB and the MFP
control PWB
Slave unit PWB mother
board connector pin
breakage
Check connection of the
connector between the
slave unit PWB and the
MFP control PWB and
the harness.
Check grounding of the
machine.
AR-M550/M620/M700 SELF DIAG MESSAGE AND TROUBLESHOOTING 9 - 14
Main Sub Auto developer adjustment trouble
Title
code code (Overtoner error)
EE EL Phenomenon Display
Details
Section
Operation
mode
Note
Case 1 Trouble
position/
Cause
Remedy
Note
Main Sub Auto developer adjustment trouble
Title
code code (Undertoner error)
EE EU Phenomenon Display
Details
Section
Operation
mode
Note
Case 1 Trouble
position/
Cause
Remedy
Note
Lamp
Message
Auto developer
adjustment trouble
(Overtoner error)
When executing the
automatic development
adjustment, toner
concentration sensor
output level is 1.5V or
below.
Engine
Toner density sensor
trouble
Charging voltage and
developing voltage
trouble
Toner density trouble
Developing unit trouble
PCU PWB trouble
Use SIM 25-2 to perform
the automatic developing
adjustment.
Lamp
Message
Auto developer
adjustment trouble
(Undertoner error)
When executing the
automatic development
adjustment, toner
concentration sensor
output level is 3.5V or
above.
Engine
Toner density sensor
trouble
Charging voltage and
developing voltage
trouble
Toner density trouble
Developing unit trouble
PCU PWB trouble
Use SIM 25-2 to perform
the automatic developing
adjustment.