Ricoh G188 Service Manual page 385

Test pattern check
SM Appendix
Possible cause/Countermeasure
Drum phase adjustment error
1. Do SP1-902-001 (Drum phase adjustment); see
Replacement and Adjustment – Drive Unit – Gear
Unit for details.
2. Reinstall or replace the PCU.
3. Check or replace the drive unit.
5-9
Troubleshooting Guide
G188/G189