LG F1200 Service Manual page 41

4. TROUBLE SHOOTING
Charging is operating properly
(3) LCD Display Trouble
• LCD Control signals from Main Board
- LCD_RST, LCD_CS, LCD WR, LCD_ADS, MLED, LCD_D(0)~LCD_D(7)
• Check Points
- The Assembly status of the LCD Module
- The Soldering of connector
- The FPCB which connects the LCD Module
• Trouble Shooting Setup
- Connect PIF Jig, and Power on
START
I/O Connector (CN405)
Is well - soldered ?
Yes Yes
Voltage at pin 4,6 of Q400
Yes Yes
Q400,D400,R407 are
soldring well?
Yes Yes
Voltage across R407
Yes Yes
Battery is OK ?
Yes Yes
Resolder the CN405
No No
(Pin 4,5: VCHG,
Pin 12,19,25,26 : GND)
No No
The TA is out of order.
Change the TA
No No
Resolder the Q400,D400,R407
Replace the Q400, D400
No No
The Battery may have
Problems. Change battery.
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