Troubleshooting Guide - LG Flatron L1730SF (L1730SFN.A**MEP) Service Manual

NO POWER
(POWER INDICATOR OFF)
CHECK J403
PIN5, PIN6 (5V)?
U301 PIN2 VOLTAGE
CHECK KEY CONTROL
CONNECTOR ROUTINE
PIN75 (3.3V)
VOLTAGE ?
CHECK U201 PIN 96
1
CHECK U201
Waveforms
1
U201-#96
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Only for training and service purposes

TROUBLESHOOTING GUIDE

VOLTAGE
YES
CHECK
(3.3V) ?
YES
IS U201
YES
PULSE
YES
1. NO POWER
NO
NO
NO
NO
- 15 -
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
LGE Internal Use Only