LG LM-W550A Service Manual page 13

IC302, 202 (BU2090) Troubleshooting
IC301, 201 16PIN power impression check
YES
IC302,202 95,2,3PIN CLK data check
YES
CONTROL function check
YES
NORMAL
IC401 (NJW1190) Troubleshooting
IC401 24PIN power impression check
YES
IC401 22,23 Pulse waveform check (VOL UP,DOWN check while rotating VOL UP, DOWN
YES
IC401 20,25 PIN waveform output check
YES
IC401 7,37PIN(TAPE) input waveform check
YES
IC401 6,39(TUNER) PIN input waveform check
YES
IC401 8,37(CD) PIN input waveform check
YES
IC401 9, 36(AUXO input waveform check
Nomal
NO
SMPS power check
NO
IC301 95,34,4PIN data check(When switching CD, TAPE FUNCTION)
Pattern check between IC301 and IC501
NO
Replace IC302, 202
NO
Refer to SMPS power check
NO
IC301 10,8PIN check
MICOM(10,8) - IC601(21,22) PATTERN check
NO
Replace IC601
NO
TAPE Troubleshooting
NO
TUNER module replacement
NO
CD Troubleshooting
NO
Replace IC401
- 2-6 -
NO
YES
Refer to IC301 Troubleshooting
IC301, IC501 PATTERN check
NO
YES
IC301 Troubleshooting