Bang & Olufsen BeoLab 17, Service Manual

Page: 18 / 72

2.12 Fault flow chart
Fault symptom:
Distorted sound from speaker
Possible causes:
Defective PCB04, Power Supply
Defective PCB30, Digital Sound Engine
Defective PCB35, Amplifier
Defective PCB89, Wireless Power Link Rx
Defective speaker unit
Distorted sound
from both speaker
units?
No
Locate and replace
the distorted
speaker unit
OK?
Replace PCB30,
Digital Sound
Engine
Yes
Survey of plugs and pins - see page 2.13
** Confirm 28V at
PCB04, P4 pin 1, 2
and -28V at PCB04,
P4 pin 7, 8
OK?
Replace PCB04,
Power Supply
Replace PCB30,
Digital Sound
Engine
Confirm 3V at
PCB04, P3 pin 3
OK?
Check connection
between PCB04,
Power Supply and
PCB30, Digital
Sound Engine
OK?
Repair/replace
connection
Confirm 1.6V at
PCB89, P7 pin 22
and 3.3V at PCB89,
P7 pin 24
OK?
Connect
ServiceTool and
read out Error Log.
Any suggestions?
Replace PCB89,
Wireless Power
Link Rx
Replace the
suspected module
related to the
error log
Replace PCB30,
Digital Sound
Engine
Replace PCB35,
Amplifier
Use ServiceTool to
calibrate the new
module
Disconnect W4
from PCB35, P3.
Confirm 28V at
PCB04, P4 pin 1, 2
and -28V at PCB04,
P4 pin 7, 8
OK?
**
Set BeoLab 17 in service position 2
for measuring on modules. See
replacement of modules page 4.8