Troubleshooting
4-1
4. Troubleshooting
4-1 DCU Control
In case of ML-6060,you can not use the DCU under ‘Diagnostic mode’
But, you can check set condition by status code
4-1-1 DCU Setup
1) Connect DCU to Controller Board Connector CN9 (4 pins)).
4-1-2 DCU Error Status Code
DCU error code will indicate malfunction area of the machine.
Display Error status
60 OPEN FUSER ERROR
62 LOW HEAT ERROR
68 OVER HEAT ERROR
64 COVER OPEN ERROR
70 NO PAPER or NO CASSETTE
71 PAPER JAM 0
72 PAPER JAM 1
73 PAPER JAM 2
95 LSU NOT READY
4-1-3 Error Solution
Display Solution
60, 62, 68 1. Measure the resistance of the AC connector on the Fuser. Normal resistance is 2-4 ohms
for 110V, 6-8 ohms for 220V.
2. Check if the fuser lamp works properly.
3. Measure the resistance at Q7 on the engine board. If abnormal, replace U503,CN502,
70 1. Make sure that paper is loaded in the cassette.
2. Replace U555 sensor (photo interrupter).
3. Replace U7 on controller board.
71 1. Make sure that paper is loaded in the cassette.
2. Check for pick-up unit. If it is heavily worn, replace it with new one.
3. Replace U554 sensor.
4. Check if the feed clutch works properly.
5. If abnormal, replace the feed clutch or Q3 on the Engine board .
72, 73 1. Make sure that the paper being used meets the specification.
2. Check if there is a paper jam in the fuser.
3. Replace U554 on the engine board or exits ensor on the frame.
4. Check the fuser roller for any dirt. If dirty, clean the roller.
95 1. Check for CN11,CN6 on the Controller board.
2. Replace U5,OSC1 on the Engine board.
3. Replace LSU.
Troubleshooting
4-2
4-2 Abnormal Image Printing and Defective Roller
If abnormal image prints periodically, check the parts shown below.
No Roller Abnormal image period Kind of abnormal image
1 OPC Drum 95.6mm White spot/Black spot
2 Charge Roller 38.5mm Black spot
3 Supply Roller 45.3mm Horizontal density band
4 Develop Roller 47.1mm Horizontal density band
5 Transfer Roller 56.1mm Black side contamination/transfer fault
6 Heat Roller 69.3mm Black spot and fuser ghost
7 Pressure Roller 72.5mm Black side contamination
Troubleshooting
4-3
Repair or replace the GND
terminal.
Check the path between
video controller, engine board
and HVPS. Repair or replace
the defective component
or board.
The mirror in LSU might be misplaced so the light
path to the OPC deviates ->Repair or replace LSU
or remove any defective matters in the machine.
No image?
Is the OPC
terminal of machine
well-connected
to Frame?
Does the
video data line to
LSU transit to High/Low
when printing?
A on
next page
NO
NO
NO
Repair or replace he
GND terminal
Is the
OPCshaft of CRU
well-connected to
GND terminal
NO
YES
YES
YES
YES
4-3 Print Quality
4-3-1 No Image
Notice
In the ML-6060 Series system, the Developing/Supplying bias is set to decrease by -50V increments when
the system load is over the specified value. Therefore, if you check the bias without the toner cartridge, the
system load is recognized to be infinity and Developing/Supplying bias decreases by -50V increments.
At the first warm-up after the printer is powered on and then off, the software does not have the data on
system load, so the Developing/Supplying bias measures -500V/-650V, the basic voltage.
And, from the second warm-up and on, the software has the data on system load, so the bias measures
-450V/-600V, which is less -50V than the basic voltage.
Without cartridge First Warm-up Second Warm-up
Developing Bias -500V -450V
Supplying Bias -650V -600v
Troubleshooting
4-4
Transfer roller might be out of its location.
-> Locate the roller into its place.
This could occurrs when the power of LSU is low or
the density is low due to the obstacles on the window
-> Replace LSU or clean the window.
A
Transfer
voltage OK? (on the
transfer roller
shaft)
Are the
connection terminal
and connection
correct?
Repair or replace terminal.
Sealing tape
is removed from the
cartridge?
Replace HVPS or repair defective component.
Is the connection
terminal OK?
Replace HVPS or repair
defective component.
Repair or replace terminal.
Remove the tape.
Developing
and supplying
voltage
are OK?
Does the
counter indicate over
the toner's guarranty
life?
Replace the toner cartridge.
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
(
(
Normal
Without Cartridge
Developing -500V -450V
Supplying -650 -600V
(
(
Troubleshooting
4-5
All black in
printing area?
Is the
Hsync/ signal received
in LSU?
Is Main high
Voltage supplied
from HVPS?
Does the
video data line to LSU
transit to High/Low when
printing?
Replace LSU.
Check the path among video
controller, engine board,
HVPS, LSU for the shortage
or open. -> Repair or replace
the boards.
Replace LSU.
NO
NO
Is C/R
well connected to
Main high voltage
terminal?
NO
Repair orReplace HVPS.
Repair orReplace terminal.
NO
NO
YES
YES
YES
YES
4-3-2 All Black
Troubleshooting
4-6
White line
missing definitely?
Dirt of dust stuck onto the
window of internal lens of LSU
-> Clean it or replace LSU.
Preventive obstacles through
the path between OPC of
developer and LSU prevent the
path -> Remove the obstacles.
Dirt of dust stuck onto the
external glass of LSU
-> Remove the obstacles.
Check if the
printout is still has the
same problem even right after
passed through the
transfer roller.
Toner material might be stuck to
blade in the developer inside and it
prevents toner supply -> Replace
the developer.
Check both if the toner cartridge's
counter is over its guaranty and
amount of the toner material.
-> Replace the toner cartridge.
The ribs in fuser or toner on the
roller may invoke the image
problem. -> Replace the fuser
cover or the defective part.
The image is originally black or the
black part is far close to the top.
-> Use the pattern which has the
image below bigger than 10mm
from the top.
NO
NO
YES
YES
4-3-3 Vertical White Line (Band)