Scattered Toner Around Solid Image Area In 1C Mode; Yellow/Brown Background During Long Runs; Fire Fly Spots - Ricoh A109 Service Manual

3.3 SCATTERED TONER AROUND SOLID IMAGE AREA IN 1C MODE.

Increase the transfer belt bias for low humidity to correct this symptom.
Adjustment range: From 100% (2000V) to 140% (2800V)
If you have the following side effect, decrease the setting to reduce the side
effect to and acceptable level:
1) The edge of letters become blurred with scattered toner (Toner
scatters not all over around the image but along the letter edges as
thin lines.)
You should also check if using fresh paper can improve copy image.

3.4 YELLOW/BROWN BACKGROUND DURING LONG RUNS

Residual voltage on OPC drum. The OPC drum may need to be replaced.
The replacement interval is 40,000 scans. Please refer to the PREVENTIVE
MAINTENANCE SCHEDULE ON PAGE 4-48

3.5 FIRE FLY SPOTS

CAUSE:
1. DEVELOPER IS TRANSFERRED TO THE DRUM - Toner concentration
is detected by the Toner Sensor located inside the Development Unit. If a
multi-copy run of high image area (image area higher than 60% per
color) is made just prior to a Toner (Near) End Condition, The toner
concentration rapidly decreases and the carrier (developer) may be
transferred to the drum.
NOTE: When the Fiery Controller is used, the Toner (Near) End
Condition is indicted on the Fiery display. If the customer does
not notice this message and opens/closes the copier front cover
the toner recovery mode is activated regardless of whether or
not toner has been added. As a result, the Toner (Near) End
Condition is reset. Therefore, the toner has been concentration
continues to decrease until Toner End is detected.
2. MELTED "BLOCKS" OF TONER ARE TRANSFERRED TO THE PAPER
- If the temperature inside the Development Unit becomes hot enough,
toner (near the DV Unit bushings) melts into small "blocks". Then, when
these "blocks" are transferred to the paper, the fire flies appear on the
copiers. Also, during maintenance of the Development Unit (replacing
developer), the melted toner around the bushings may fall into the tank
with the fresh developer. In this case, the Fire Flies will appear on the
first several copies only and decrease with use.
NOTE: Ordinarily, the temperature inside the Development Unit does
not reach that which would melt toner. However, it is possible if
one or more of the following conditions exist(s):
a) The fan filters are very dirty.
b) The cooling fans do not work.
c) If the copier has a sorter installed, the sorter exhaust fan does
not work.
FSM 6-27
Rev. 11/8/96
A109