LG KU580 Service Manual - Page 49

3. Technical Brief 3.2.7 LCD Backlight Illumination There are 4 white LEDs in LCD Backlight circuit which is driven by Charge Pump(MAX8631). APP_GP10_BL_CTRL is used for Backlight brightness control. VBAT APP_GP10_BL_CTRL APP_GP03_CAM_LDO_CTRL ESD9X5.0ST5G INSTPAR ZD101 C102 10u U101 1 2 PIN IN MAX8631XETI C1P 23 3 24 GND 29 PGND BGND C1N C2P 22 26 C2N 27 OUT 25 20 19 ENM1 ENM2 21 ENF 18 ENLDO 28 17 P1 P2 8 SETM 7 SETF 6 REFBP M1 16 M2 15 M3 M4 14 13 12 F1 F2 11 F3 F4 10 9 LDO1 4 5 LDO2 C107 0.01u C101 1u C104 1u C103 10u LCD_BL1 LCD_BL2 LCD_BL3 LCD_BL4 C108 C109 1u 1u CPO VCAM_2V8 VCAM_1V8 R116 100K R117 100K R118 100K R121 1% 6.8K R122 1% 10K Figure 3-2-10. Charge Pump Circuit LCD Backlight 3.2.8 Keypad Illumination There are 12 red LEDs in Main board backlight circuit, which are driven by ACC_GP16_KEY_LED_ON (Main_LED_ONOFF_Main) line from DB3100. VBAT ACC_GP16_KEY_LED_ON R531 100K R517 2.2K R518 36 R532 36 123 Q501 EMX18 654 R519 R520 R521 R522 R523 R524 R525 R526 R527 R528 R529 R530 150 LD500 SSC-FR104-II1 150 LD501 SSC-FR104-II1 150 LD502 SSC-FR104-II1 150 LD503 SSC-FR104-II1 150 LD504 SSC-FR104-II1 150 LD505 SSC-FR104-II1 150 LD506 SSC-FR104-II1 150 LD507 SSC-FR104-II1 100 LD508 SSC-FR104-II1 100 LD509 SSC-FR104-II1 100 LD510 SSC-FR104-II1 100 LD511 SSC-FR104-II1 C518 0.1u Figure 3-2-11. Keypad Backlight LED Interface and Backlight Circuit LGE Internal Use Only - 50 - Copyright © 2007 LG Electronics. Inc. All right reserved. Only for training and service purposes