Troubleshooting - Ricoh A028 Service Training Manual

Process Control

2.11.5 Troubleshooting

The grid output rises.
The flash output rises.
Some OPC potentials displayed by service tool [4-01] are 994
volts or 0 volt. However, the ID sensor potential is 972 volts or 0
volt. As a result, black or white (blank) image occurs.
The flash output rises. (shortens the service life of the lamp.)
The grid output fluctuates. Also, the flash output fluctuates and
shortens the life of the lamp.
The grid output rises. The flash output also increases, shortening
the life of the lamp.
The flash output fluctuates, and shortens the life of the lamp.
Because fluctuations are reflected in the compensation values for
the grid and flash outputs (shift steps), images vary temporarily
but are returned to previous image values by the process control.
Same as above.
Problem
Potential sensor A contaminated by toner.
Potential sensor B contaminated by toner.
Potential sensor does not function (no output).
The white pattern is dirty.
The black pattern is dirty.
Abnormal target VD setting.
Abnormal target VL setting.
Abnormal grid setting.
Abnormal flash setting.
2-88
Probable Cause
1 July 1994