Troubleshooting Guide - LG Flatron L1750SQ-SN Service Manual

NO POWER
(POWER INDICATOR OFF)
CHECK J705
VOLTAGE
PIN5, PIN6 (5V)?
CHECK
U501 PIN 8 Voltage
(5V) ?
CHECK KEY CONTROL
CONNECTOR ROUTINE
IS U201
PIN90 (3.3V)
VOLTAGE ?
CHECK U201 PIN 96
1
PULSE
CHECK U201
Waveforms
1
U201-#96

TROUBLESHOOTING GUIDE

1. NO POWER
YES
YES
YES
YES
- 14 -
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CHECK POWER BOARD,
NO AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE
NO
CHECK 5VS LINE
(OPEN CHECK)
NO
CHECK 3.3V LINE
NO
CHECK X-TAL
NO PROBLEM