LG Flatron L1754SM, Service Manual

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5
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TROUBLESHOOTING GUIDE
1. NO POWER
NO POWER
(POWER INDICATOR OFF)
NO
CHECK POWER BOARD,
AND FIND OUT A SHORT
POINT AS OPENING
EACH POWER LINE
NO PROBLEM
1
Waveforms
IC5
01-#96
CHECK KEY CONTROL
CONNECTOR ROUTINE
CHECK
IC5
01
NO
NO
CHECK 3.3V LINE
(OPEN CHECK)
CHECK 3.3V LINE
NO
CHECK X-TAL
YES
CHECK J
7
03
VOLTAGE
PIN5, PIN6 (5V)?
CHECK
IC7
01 PIN2 VOLTAGE
(3.3V) ?
IS
IC5
01
PIN
75
(3.3V)
VOLTAGE ?
CHECK
IC5
01 PIN
96
PULSE
1
YES
YES
YES