Bang & Olufsen BeoSound 4 2851 Service Manual page 17

Fault symptom:
- Unable to play DAB
- CD plays OK
- FM plays OK
Possible causes:
- PCB3, DAB
- PCB6, SMPS
Fault symptom:
- Unable to open front glass
Possible causes:
- PCB3, Magic door censor
- PCB6, SMPS
- Motor
Replace PCB6, SMPS
Measure voltages +6V
DAB aerial is mounted
Measure connections
to DAB OK
Replace PCB3, DAB
Lift the glass so the
keyboard is visible
Measure connection
Press the "Load"
to PCB3, Magic
button
The front glass slides
up?
BS4 in service position
Measure connection to
PCB3, Magic Change PCB6, SMPS
Confirm voltage
5V_SB & 6V
Change PCB3, Magic
Change PCB2, Master
OK?
Fault flow chart
Yes
Measure voltages
Change PCB6, SMPS
5V_SB & 6V
Change PCB2, Master
Change PCB3, Magic
2.9
No