HP 3015 Service Manual - Page 100

This circuit also controls the image density by changing the primary ac voltage and the developing ac bias according to the print density setting (which is set by using the HP Toolbox). High voltage is disabled when the print-cartridge door is open. The following Figure 4-5. High-voltage power supply circuit figure shows this process. Engine controller PCB Power supply PCB IC902 CPU PRPWM J902-10 J201-14 PRAC J902-9 J201-15 High-voltage power supply circuit Primary charging bias circuit IC301 IC301 IC301 DC voltage generation circuit Combined AC voltage generation circuit Primary PR1 J304 charging roller Photosensitive J303 drum DVAC J902-8 J201-16 TRPDC J902-6 J201-18 TRNDC J902-7 J201-17 TRCRNT J902-2 J201-22 Developing bias circuit DC voltage generation roller circuit IC301 Combined AC voltage generation circuit Transfer charging bias circuit Positive voltage generation circuit IC501 Negative voltage generation circuit Developing DEV J301 cylinder Transfer TRS J302 charging Figure 4-5. High-voltage power supply circuit 82 Chapter 4 Operational overview ENWW