Cannot Switch On; No Picture; No Backlight - Bang & Olufsen BeoPlay V1-40 MKII Service Manual

3.4 Fault flow chart
Fault flow chart
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
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?
Confirm voltages on
PCB01, P103 pin 17
Replace PCB01,
PS_ON on
Video Engine
approx. = +5V
OK?
Confirm voltage on PCB01, P103
pin 1, 3, 5 12V = +12V,
or alternatively PCB04, P18
pin 1, 3, 5 P12V = +12V
OK?
See
page
3.5
Confirm that
Replace cable or
PCB04, Pxxx has
re-establish
mains voltage
connection
OK?
Is remote control Replace remote
OK?
Confirm voltage on Confirm voltage on
PCB01, P101 pin 3 PCB01, P103 pin 7
5V_SB_F = +5V 5V_SB = +5V
OK?
Check cable
Replace cable or
between PCB01,
re-establish
P101 and PCB58, P1
connection
OK?
Confirm voltages on PCB01, P101 pin 4
change from 5VDC to approx 3.8VDC when a
coloured button on the remote control is
Disconnect both cable(s) to PCB35, P1.
Connect to mains and switch product on.
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.
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
Is LED
on TV front
control
Off?
Check cable
connection
between PCB04,
P18 and PCB01,
OK?
P103 OK?
Replace PCB01,
Video Engine
pressed
OK?
Disconnect product from mains.
Confirm voltage on PCB04, P18
pin 1, 3, 5 P12V = +12V OK?
*
Disconnect the product from mains.
OK?
*
PCB04 12 V supply
No
Yes
See LED indication
table page 3.3
Replace cable or
re-establish
connection
Replace PCB04,
Power Supply Unit
Replace PCB58, IR
Receiver & Room
Awareness
Replace PCB04,
Power Sypply Unit
Replace PCB35,
ICEpower Amplifier
that was latest
reconnected
Hint:
Measurement plugs,
pins and test points;
see page 3.17-3.18