Pwm Modulation Check - LG OM7560 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

4. PWM MODULATION CHECK

PWM MODULATION PART
CHECK
YES
Check CN202
pin1, 2: 12 V.
YES
• Check IC601(TAS5548) 3.3 V - pin9, 14, 35, 50.
• Check X601 (12.288 MHz).
YES
Check
X601(12.288 MHz)
operation.
YES
Check IC601 pin21 CLK input.
YES
Check IC501 (MLC3730)
pin U13: RESET, pin L14: SDA
pin L13: SCL output.
YES
Check
IC601(TAS5548) input data
pin24 PWM wave.
YES
Check
PWM modulator output
FL: Pin48(-),49(+). FR: Pin46(-),47(+).
Other output
check.
YES
OK
NO
Refer to
SMPS troubleshooting.
NO
Check X601
(12.288 MHz).
OK
NO
Check line resistor output
RST: R5T1, SCL: R550,
SDA: R595.
OK
Check
NO
CD Assy communication
Pin22, 23, 24.
Check IC601
input data.
OK
NO
Check IC601.
OK
3-27
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
Replace X601(12.288 MHz).
Replace R5T1, R559, R550.
Refer to
CD troubleshooting.
Check each line resistor output.
Replace IC601.