Samsung MM-28 Service Manual page 27

Troubleshooting
6-3-2 Audio Output Malfunction
Malfunction of Audio Output
Check voltage of NIC05 : 5V
Check waveform of NIC9223
Check waveform of NC55R,L
6-6
Yes
Yes
pin no. 12,13
Yes
Yes
Check Amp
No
Replace NIC05
No
Check NIC9223 soldering
No
Replace NIC9223
Check NIC9223 soldering
Samsung Electronics