Bang & Olufsen BeoPlay V1-40, Руководство по обслуживанию, Страница: 21 / 74

Fault flow chart 3.5
Hint:
Measurement plugs,
pins and test points;
see page 3.17
See
page
3.6
Replace PCB04,
Power Supply Unit
Confirm voltage on
PCB01, P103 pin 12,
PS_BLV_ON approx.
= +5V (high)
OK?
Replace PCB01,
Video Engine
Confirm voltages on
PCB04, P116 pin 1,
2, 3, 4, 5
P24V = 24V
(or use similar
testpoints)
OK?
Confirm voltage on
PCB01, P123 pin 4, LCD_INV_BL_ON/OFF
approx. = +5V (high)
and on PCB01, P123 pin 1, LCD_CTRL_PWM,
approx. between 0.9 and 3.3 V
OK?
Replace PCB01,
Video Engine
From page
3.4
No
Yes
Checking backlight:
Check light from Backlight LED as indicated below
LTA400HF33
When switching on TV after stand-by and backlight is missing (or e.g. is missing after a while) and sound is OK.
Problem may disppear after a new stand-by (error ocurrung intermittently). Check the following to reveal fault.
Recommended check points:
BL_ON
(4.4V to 4.8V,
OK high)
BL_Err
(3.7V, OK high)
12VCC
(internal
PCB49)
24V
from PSU
Remarks on condition
4.4 to 4.8V 3.7V 12V 24V Backlight OK
0V 3.7V 12V 24V Condition: “Picture mode” is activated; BL_ON = 0V and
LED indicator lights green:
Check if cable W24 is OK an connected correctly, PCB01 fails
4.4 to 4.8V 0V (low) 12V 24V PCB49 or connection to LCD fails (Error on LCD is very seldom)
4.4 to 4.8V 0V (low) 0V 24V PCB49 defective
4.4 to 4.8V 0V (low) 0V 0V PCB04 defective; if BLC_ON is 3.2V (PCB04, P18 pin 14)