Bang & Olufsen BeoPlay V1-40, Service Manual

Page: 20 / 74

3.4 Fault flow chart
Hint:
Measurement plugs,
pins and test points;
see page 3.17-3.18
Fault symptom:
Cannot switch on
No picture
No backlight
Possible causes:
Remote Control
PCB58, IR Receiver & Room Aware.
PCB04, Power Supply Unit
PCB01, Video Engine
PCB35, ICEpower Amplifier
PCB49, Backlight Driver
LCD panel
Replace cable or
re-establish
connection
See LED indication
table page 3.3
Confirm voltage on PCB01, P103
pin 1, 3, 5 12V = +12V,
or alternatively PCB04, P18
pin 1, 3, 5 P12V = +12V
OK?
Disconnect product from mains.
Disconnect both cable(s) to PCB35, P1.
Connect to mains and switch product on.
Confirm voltage on PCB04, P18
pin 1, 3, 5 P12V = +12V OK?
*
Disconnect the product from mains.
Reconnect cable to PCB35, P1 (one at a time);
Connect to mains and switch the product on.
Confirm voltage in PCB35, P1 pin 4 = 12V.
OK?
*
When the ICEpower Amplifier is faulty the
behaviour of the measurement is that the
voltage will drop to <1 V and then slowly lower
to approx. 0.3V due to short circuit of the
PCB04 12 V supply
Press TV on remote control and look at the
standby light.
Is the green LED solid on or does it blink a
number of times?
Is remote control
OK?
Confirm voltages on PCB01, P101 pin 4
change from 5VDC to approx 3.8VDC when a
coloured button on the remote control is
pressed
OK?
Check cable
between PCB01,
P101 and PCB58, P1
OK?
Confirm voltages on
PCB01, P103 pin 17
PS_ON on
approx. = +5V
OK?
Replace PCB01,
Video Engine
Confirm voltage on
PCB01, P101 pin 3
5V_SB_F = +5V
OK?
Confirm voltage on
PCB01, P103 pin 7
5V_SB = +5V
OK?
Replace PCB01,
Video Engine
Replace remote
control
Check cable
connection
between PCB04,
P18 and PCB01,
P103 OK?
Replace cable or
re-establish
connection
No
Yes
Confirm that
PCB04, Pxxx has
mains voltage
OK?
Is LED
on TV front
Off?
Replace PCB04,
Power Supply Unit
Replace PCB58, IR
Receiver & Room
Awareness
Replace PCB35,
ICEpower Amplifier
that was latest
reconnected
Replace PCB04,
Power Sypply Unit
Replace cable or
re-establish
connection
Fault flow chart
See
page
3.5