Gestetner G060, Service Manual

Page: 129 / 1106

SC TABLE
SM 4-15 G060
SC No. Item Definition Possible Cause
Related
SCs
Troubleshooting Procedure Type
SC 390 Development
Bias output
error The high voltage supply board
(C/B) monitors the circuit and
detects abnormal conditions
such as a voltage leak or no
output condition. If this
happens, the high voltage
supply board sends an error
signal (High to Low at CN204-
A18) to the BCU.
The BCU monitors this signal
every 2 ms and generates this
SC code when the error
condition occurs 250
consecutive times.
•
Loose connection
•
Defective power pack
C/B output
•
Damaged cable
•
Defective
development unit
•
Defective BCU
1. Turn the main switch off and on.
2. Check if the harness and cables are
properly connected.
3. Disconnect the high voltage supply
cables from the bias terminals on the
high voltage supply board C/B.
Measure the DC voltage using a
multi-meter.
•
Replace the high voltage supply
board if no voltage is supplied.
4. If the result is OK at step 2, check if
the high voltage supply cable or
development unit is grounded.
•
Replace the high voltage supply
cable if it damages.
•
Replace the development unit if it
damages.
5. Check the PWM signals are sent to
the high voltage supplied board from
the BCU. Replace the BCU or
harness between the BCU and high
voltage supply board if the voltage is
0.
SC 391-
01 Charge AC:
output error
391-01: K
391-02: Y
391-03: M
391-04: C The high voltage supply board
sends the feedback signal
(CN228-2 to 5; MCYK). The
BCU monitors these feedback
signals every 8 ms. If the
average of the sampled data is
not within the control target 30
consecutive times, this SC
code is generated.
•
Power pack
disconnected
•
Charge receptacle or
terminal
•
Defective PCU bias
input terminal
•
Incorrect power pack
B/C output
•
Damaged cable
•
Defective BCU
1. Turn the main switch off and on.
2. Check the connector.
3. Check the PCU charge voltage input
(the spring/conducting shaft) or
replace the PCU.
4. Replace the power pack B/C.
5. Replace the cable.
6. Replace the BCU.