THEORY
Electrical
SERVICE MANUAL
2-22
9.3.
LCD Drive Voltage (VEE) Generation Circuit
The polarity of the LCD drive voltage (VEE) differs according to the LCD module.
Fig. 2.23 shows the circuit for the LCD module driven by the minus VEE voltage. The
+5 VDC source voltage is switched continuously by the 20 kHz pulses from CBIC (#8) to
energize L5. The reverse voltage generated by L5 is rectified by D6 and regulated by
ZD5. The ZD5 determines the VEE voltage (about -16 V).
The LCD module driven by the plus VEE voltage uses the circuit shown in Fig. 2.24.
The +24 VDC source voltage is switched continuously by the 90 kHz pulses from CBIC
(#8) to energize L2. The voltage generated by L2 is rectified by D5 and regulated by
ZD4 and ZD6. The ZD4 and ZD6 determine the VEE voltage.
VEE voltage is adjusted by turning VR1.
Fig. 2.23 LCD Drive Voltage Generation Circuit (Minus Voltage VEE)
Fig. 2.24 LCD Drive Voltage Generation Circuit (Plus Voltage VEE)
Summary of Contents for DP-550CJ
Page 15: ...THEORY SERVICE MANUAL Mechanical 1 3 Fig 1 2 General View of Printing Mechanism ...
Page 20: ...THEORY Mechanical SERVICE MANUAL 1 8 Fig 1 7 Printer Flat Cable to Cartridge Alignment ...
Page 21: ...THEORY SERVICE MANUAL Mechanical 1 9 Fig 1 8 Ink Jet Cartridge to Flat Cable Alignment ...
Page 33: ...THEORY SERVICE MANUAL Mechanical 1 21 Fig 1 17 LCD Unit Installation in the Upper Cover ...
Page 34: ...THEORY Mechanical SERVICE MANUAL 1 22 DP 525CJ LW 800ic Fig 1 18 LCD of DP 525CJ LW 800ic ...
Page 38: ...THEORY Electrical SERVICE MANUAL 2 2 Fig 2 1 Major Electronic Component Parts ...
Page 80: ...REPAIR SERVICE MANUAL Troubleshooting 3 17 Fig 3 5 Results of Self Print Test ...
Page 118: ...REPAIR SERVICE MANUAL Mechanical 4 3 Fig 4 2 Removing the Sub Paper Support and Paper Support ...
Page 124: ...REPAIR SERVICE MANUAL Mechanical 4 9 Fig 4 6 Removing the LCD Unit ...
Page 127: ...REPAIR Mechanical SERVICE MANUAL 4 12 DP 525CJ LW 800ic Fig 4 8 Removing the LCD PCB 1 ...
Page 128: ...REPAIR SERVICE MANUAL Mechanical 4 13 DP 530CJ LW 810ic Fig 4 9 Removing the LCD PCB 2 ...
Page 129: ...REPAIR Mechanical SERVICE MANUAL 4 14 LW 810icBL Fig 4 10 Removing the LCD PCB 3 ...
Page 130: ...REPAIR SERVICE MANUAL Mechanical 4 15 DP 540CJ Fig 4 11 Removing the LCD PCB 4 ...
Page 131: ...REPAIR Mechanical SERVICE MANUAL 4 16 DP 550CJ LW 840ic Fig 4 12 Removing the LCD PCB 5 ...
Page 134: ...REPAIR SERVICE MANUAL Mechanical 4 19 Fig 4 14 Installing LCD Latch ...
Page 139: ...REPAIR Mechanical SERVICE MANUAL 4 24 Fig 4 18 Installing the Hinge Assy ...
Page 154: ...REPAIR SERVICE MANUAL Mechanical 4 39 Fig 4 30 Removing the Hopper Assembly ...
Page 162: ...REPAIR SERVICE MANUAL Mechanical 4 47 Fig 4 38 Removing the Carriage ...
Page 171: ...REPAIR Mechanical SERVICE MANUAL 4 56 Fig 4 45 Measuring Friction during Carriage Movement ...
Page 178: ...REPAIR Mechanical SERVICE MANUAL 5 2 Fig 5 1 Carriage Assembly Lubrication Points ...
Page 179: ...REPAIR SERVICE MANUAL Mechanical 5 3 Fig 5 2 Paper Feed Assembly Lubrication Points ...
Page 194: ...Feb 98 53T010BE1 R ...