Bang & Olufsen DVD 2, Service Manual

Page: 14 / 70

3.2 Fault flow chart
Confirm the mains
supply is connected
and applied
OK?
Fault symptom:
No start up
No STBY. LED (normally red)
No Display
Possible causes:
Mains not supplied
Blown fuse F on PCB04, Power Supply
Missing voltages
Defective PCBs
Defective cables
Reconnect J2 on PCB04, Power Supply
Disconnect cable P0 on PCB4,
Keyboard
Confirm:
+3.3V Stby. on PCB04, J2 pin 5
+5V Stby. on PCB04, J2 pin 3
+2V Stby. on PCB04, J2 pin
OK?
Replace PCB04,
Power Supply
Disconnect J2 on PCB04, Power Supply
Confirm:
+3.3V Stby. on PCB04, J2 pin 5
+5V Stby. on PCB04, J2 pin 3
+2V Stby. on PCB04, J2 pin
OK?
Confirm:
+3.3V Stby. on PCB04, J2 pin 5
+5V Stby. on PCB04, J2 pin 3
+2V Stby. on PCB04, J2 pin
OK?
Replace fuse F on
PCB04 and connect
to mains
Does fuse F on
PCB04, Power Supply
blow again?
Fuse F on PCB04,
Power Supply
OK?
Replace/reconnect
mains cable
Replace PCB4,
Keyboard
Replace PCB03,
Display
Replace PCB0,
Analog
Reconnect P0 on PCB4
Disconnect P00 on PCB4, Keyboard
Confirm:
+3.3V Stby. on PCB04, J2 pin 5
+5V Stby. on PCB04, J2 pin 3
+2V Stby. on PCB04, J2 pin
OK?
Replace PCB04,
Power Supply
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