LG MICRO Hi-Fi SYSTEM Service Manual page 22

11. TUNER FUNCTION PART CHECK
TUNER FUNCTION PART CHECK
Check TUNER
module(TU100) is working
Check IC300(CS5346)
23, 24pin input waveform
Check IC300(CS5346)
41pin output waveform
OK
YES
YES
YES
YES
NO
Check TUNER module power
NO
Replace the related parts
3-9
(check 4pin 9V)