Canon imageRUNNER ADVANCE C2000 Series Technical Workbook page 117

Cause
DDR2-SDRAM mounted on Main Controller PCB 1 had a failure.
Service work
When the symptom occurs, follow the steps below to replace the DDR2-SDRAM (FK2-8341-000) [1].
1) Turn OFF the main power.
2) To perform Controller System Error Diagnosis, hold down digit keys "2" and "4" on the control panel at the
same time while turning on the main power. Keep pressing these keys until the following Controller System
Error Diagnosis are displayed. It takes about 20 seconds.
pg. 115