Pwm Modulation Check - LG OM4560 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

5. PWM MODULATION CHECK

PWM MODULATION PART
CHECK
YES
Check
L605(PWM_3.3V).
YES
• Check IC700(TAS5548) VDD 3.3 V - Pin9, 14, 35, 50.
• Check X701 (12.288 MHz).
YES
Check
X701(12.288 MHz)
operation.
YES
Check IC701 Pin21 CLK input.
YES
Check IC502(MLC3730S)
Pin B3: PWM_RST, Pin A1: PWM_DATA
Pin A2: PWM_CLK output.
YES
Check
IC701(TAS5548)
input data Pin24
PWM wave.
YES
Check PWM
modulator output
FL: Pin48(-), 49(+)
YES
OK
NO Refer to SMPS and DC-DC
convertor troubleshooting.
NO Check X701
(12.288 MHz)
OK
NO
Check input data
IC502 Pin F1, F2, G1.
Check MCS_MCLK output data
IC502 Pin D2.
Check IC502.
OK
Check
NO
Data communication
Pin24, 25.
Check
IC701 input data..
OK
NO
Check IC701.
OK
3-24
NO
YES
YES
YES
NO
YES
NO
YES
NO
YES
NO
YES
Replace X701 (12.288 MHz).
Replace IC502.
Refer to AUX or Data
troubleshooting.
Check each line
resistor output.
Replace IC502.