Print Quality Problems; All-Black Printout - Mita DP-2800 Service Manual

Print quality problems

Print quality problems range from uneven tone to completely blank output. The troubleshooting
procedure for each type of problem is given below.
Completely blank printout
Check the developer unit.
Check main charging potential.
Check the laser scanner.

All-black printout

Check the main charger unit
installation.
Check the grid plate (the
mesh metal bottom part of the
charger unit).
Check the drum bias.
Check high voltage potential
at the HV board.
• Check that the developer unit is inserted correctly
• Check that the developer's connector is connected
properly.
• Check that toner is adhered around the developing
roller. If no toner appears to be on the roller, try feeding
toner into the developer using the manner described in
chapter 3 (See page 3-9).
• Check the main charging output on the HV board. This
requires removal of the left side cover and the test
equipment. Replace the HV board if high voltage
potential is not available on the board.
• The scanner components within the scanner may be
disordered. Note that the laser scanner is concealed to
protect the components which are susceptible to dust.
It should not be disassembled except within a dust-free
chamber. Replace the scanner unit if necessary.
• Open the printer side cover and check that the main
charger unit is correctly seated. To do this, take out the
main charger unit from the printer; then reinstall it
carefully.
• The grid plate must be flat and fit horizontally in place.
Replace the main charger unit if necessary.
• Make sure the bias from the HV board is correctly
arrived at the drum unit.
• Check the high-voltage output on the HV board. This
requires removal of the left side cover and the test
equipment. Replace the HV board if high voltage
potential is not available on the board.
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