Troubleshooting Guide - LG FLATRONL1753S Service Manual

NO POWER
(POWER INDICATOR OFF)
CHECK J703
VOLTAGE
PIN5, PIN6 (5V)?
U601 PIN2 VOLTAGE
(3.3V) ?
CHECK KEY CONTROL
CONNECTOR ROUTINE
IS U201
PIN75 (3.3V)
VOLTAGE ?
CHECK U201 PIN 96
1
CHECK U201
Waveforms
1
U201-#96

TROUBLESHOOTING GUIDE

1. NO POWER
YES
CHECK
YES
YES
PULSE
YES
NO
NO
NO
NO
- 16 -
CHECK POWER BOARD,
AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE
CHECK 3.3V LINE
(OPEN CHECK)
NO PROBLEM
CHECK 3.3V LINE
CHECK X-TAL