Bang & Olufsen BeoSound 4 2851 Service Manual page 16

2.8 Fault flow chart
Fault symptom:
- Fault in display
- Only a few lines are faulty
Possible causes:
- PCB0, display
- Connections to display
Fault symptom:
- Fault in display
- Nothing in display
- Stand-by led OK
- Able to remote
- Able to play CD
Possible causes:
- PCB0, display
- Connections to display
Fault symptom:
- Unable to play FM
- CD plays OK
Possible causes:
- PCB85, tuner
- PCB6, SMPS
Measure connections
to the display is OK?
Change PCB0,
Change PCB2, Master
Display
OK?
Change PCB0,
Change PCB2, Master
Display OK?
Measure voltages
Replace PCB6, SMPS
+2V
Measure connections
to tuner OK
Replace PCB85, tuner
Re-establish
connection
No
Yes