Bang & Olufsen BeoSound 5, Service Manual

Page: 22 / 82

3.2 Fault flow chart
Fault symptom:
No function in BM5
Possible causes:
Defective PCB01,
Motherboard
Defective PCB4, SMPS
Defective PCB51, ML-PL
Defective 94, HDD
Confirm mains
connection is ok by
measuring on PCB4,
P19, pin1-2
OK?
Replace mains cable
OK?
Poor or defective
AC connection on
PCB04, Power
Supply
Replace PCB04,
Power Supply
Does the status LED
shine red ?
**
Push the POWER
button on the rear
panel, and confirm
the power-up
sequence
OK?
Reconnect W10.
On PCB51 confirm*:
+3V3_ATX,
+5V_ATX,
+12V_Bank
OK?
Done
Confirm 0V on
PCB51, P101 pin 9
OK?
Disconnect W9
from PCB94, HDD
and W12 from
PCB51, P150.
Confirm the before
mentioned voltages
again* OK?
Disconnect W10
from PCB04, P18,
and confirm
+12V_BUS on
PCB04, P18, pin 2-3
+5V_SB on PCB04,
P18, pin 23. OK?
Replace defective
PCB04, Power
Supply
Reconnect W9 to
PCB94, HDD.
Confirm the before
mentioned voltages
again*
OK?
Fault in
BeoSound 5.
Please refer to the
next page.
Replace defective
PCB94, HDD Power
Supply
Disconnect W5
from PCB51, P101.
Confirm the before
mentioned voltages
again*
OK?
Replace defective
PCB51, ML-PL
Replace defective
PCB01,
Motherboard
Replace defective
PCB01,
Motherboard
Replace defective
PCB01,
Motherboard
*Measuring points
PCB51
GND
+3.3V
+12V
+5V
+5V
Voltage
MASTER UNIT IR
Y Pb Pr
VIDEO
S-VIDEO DVI-I
R
5 V DC
1.0 A
L
SPDIF MASTER LINK LINE OUT POWER LINK
** Status LED on BeoMaster 5
No
Yes