Ricoh CH-C1 - RTB 176: High-pitched sound

Technical Bulletin PAGE: 1/1
Model: CH-C1 a
Date: 13-Jul-17
No.: RD135176
Subject: Troubleshooting: High-pitched sound can be heard
Prepared by: Shigeru Watanabe
From: PP CS Section, CIP PQM Department, QAC
 Classification:
 Troubleshooting
 Mechanical
 Paper path
 Part information
 Electrical
 Transmit/receive
 Action required
 Service manual revision
 Retrofit information
Product Safety
Other ( )
Tier 2
Tier 0.5
SYMPTOM
A continuous, high-pitched sound (4.4kHz) can be heard on the Model CH-C1Pro a / CH-
C1a (Pro C5100S / MP C6502SP).
Note:
- The symptom is limited to this sound; there are no other issues with the machine's
performance/quality.
- This does not occur on the Model CH-C1Pro b / CH-C1b (Pro C5110S / MP C8002SP).
- The sound level is actually below that of other normal machine sounds, including paper
feed, but the high frequency of the sound makes it more noticeable.
CAUSE
The thickness of the element tube of some OPCs is near the lower limit of specification
tolerance, which may cause harmonic resonance to occur between the OPC and charge
bias on the Model CH-C1Pro a / CH-C1a.
SOLUTION
The thickness of the element tube for the Model CH-C1Pro a / CH-C1a OPC will be
changed. If the symptom occurs on the Model CH-C1Pro a / CH-C1a, replace the current
OPC (P/N: D0749510) with the modified one (P/N: D1359510).
Note: The current D0749510 OPC is still being used on the Model CH-C1Pro b / CH-C1b,
Model Taurus-C1a/b and Model Taurus-P1 without any problem, so please continue to use
this OPC on these models.
The modification and action explained above pertains only to the Model CH-C1Pro a / CH-
C1a.