Ricoh A172 Service Manual page 485

Hide thumbs Also See for A172:

Table of Contents

Tech Service Bulletin No. A172/A199 – 016

Page 2 of 17

Checking Drum Ground

Includes Drum

1. Confirm that the Drum Shaft is grounded: Set your meter to the 200VDC Scale and check if there is

voltage present on the Drum Shaft during a copy cycle. A normal reading is less than .5 VDC.

2. If you are reading more than .5 volts at the Drum Shaft, then take a voltage reading at CN BP (#4

above) on the High Voltage Supply Board – B. If this reading is more than .5 volts, then replace the

High Voltage Supply Board – B. If this reading is less than .5 volts then check and or replace the Drum

Shaft Holder and or the Drum Shaft Terminal.

3. Confirm that the drum is grounded to the Drum Shaft: Set your meter to the 20Ω Scale and check

resistance between the drum shaft and the edge of the drum (exposed metal). A normal reading is 5Ω

or less. If this reading is more than 5Ω then clean and or reform the Drum Grounding tabs (#3 above).

NOTE1: To avoid copy quality symptoms, check that the drum is properly grounded every other PM.

NOTE2: To avoid copy quality symptoms, make sure you replace the drum lubricant bar (A1723602)

at 40k scans.

CN BP on the High

Voltage Supply Board

Drum grounding

tabs (inside drum)

Continued...