hp Color 9850mfp OTHER CONTROLS 15.4 Operation board control 15.4.1 Operation board composition II UNIT EXPLANATION 2-77 Symbol Name Function or method [16] Drum cooling fan 1 (M12) Discharging heat around the drum drive motor out of the engine [17] Drum cooling fan 2 (M13) Discharging heat around the drum drive motor out of the engine [18] Scanner cooling fan (M2) Cooling of the scanner section [19] Drum unit fan (M47) Cooling around the drum OACB OB1 TOUCH PANEL BOARD Symbol Name Function or method [1] Touch panel board Touch switch board used to directly select items shown on the LCD board (LCDB) LCDB LCD board Information of all sorts is displayed on this OB INVB OB inverter board Inverter that drives the LCD board (LCDB) OB1 Operation board 1 Control of the touch panel board, LCD board (LCDB), OB inverter board (OB INVB), operation board 3 (OB3), and the control of the LED within the operation board 1 (OB2) and the numeric pad OB2 Operation board 2 LED-loaded board to grasp the on/off condition of the reset switch (SW1) OB3 Operation board 3 Volume loaded board to adjust the brightness of the LCD board (LCDB) SW2 Main switch Power switch of the operation board It does not function when the reset switch (SW1) is off