Troubleshooting Guide - LG Flatron L2300C Service Manual

NO POWER
(POWER INDICATOR OFF)
1
CHECK J311
VOLTAGE
PIN1, PIN2 (5V)?
2 3 5
CHECK
U202 PIN4 (1.8V)
U206 PIN3 (3.3V)
U205 PIN4 (2.5V)
Voltage ?
CHECK REGULATOR
IC LINE
IS U101
PIN K17(1.8V)
/ D17(3.3V)
/H23(2.5V)
VOLTAGE ?
CHECK IIC LINE CONNECTION
(U403(24LC16),U402(MC140668))
Waveforms
1
J311-#1, 2(5V)

TROUBLESHOOTING GUIDE

1. NO POWER
YES
YES
2
3
5
YES
2 U202-#4, U101-K17
NO
NO
NO
CHECK U101 VCC, XTAL,
3 U206-#3, U101-D17
- 14 -
CHECK POWER BOARD,
AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE
CHECK 5VS LINE
(OPEN CHECK)
NO PROBLEM
RESET
5 U205-#4, U101-H23