Ricoh FW780 Service Manual - Page 173

8.1 LIGHT SENSOR ADJUSTMENT When: Purpose: Adjustment Standard: Perform: How: 1. Every Call 2. When replacing the following part • Exposure lamp • Light sensor • Drum • RAM on the main board To maintain the correct light intensity. Level 2 (10%) of the 9 step gray scale on the OS-A1 chart should be slightly visible when the 4th manual image density level is selected. Change SP #-6 setting. Change the light sensor voltage. 1. Turn off the main switch. 2. Clean the following parts: Item No. (1) (2) (3) Section Optics (Exposure glass, fiber optics array) Corona wires (charge, transfer and separation) and casing. PTL Method Damp cotton and dry soft cloth Dry cloth Dry cloth or blower brush 3. Remove the middle right cover. 4. Make several copies at manual image density level 4 with OS-A1 chart. 5. Confirm that level 2 (10%) of the 9 step gray scale is slightly visible on the copy. If the copy image density is not correct, proceed with the following step. 6. Change SP #-6 setting in the SP mode. If the image density is too dark: Increase SP #-6 setting. If the image density is too light: Decrease SP #-6 setting. 7. Confirm that image density is within the adjustment standard. SM 5-39 A163