Grundig 40VLE630BH, Руководство по обслуживанию

Страница: 85 / 180

TP CHASSIS / TELEVISION
85 September 2011
If LVDS data leaves URSA in a proper way, the problem is likely to be originated
from the panel.
Besides, you can also consider problems including that LVDS data is not being
transmitted to the panel properly, wrong panel EEPROM or software error. You can
solve the problem by installing correct software.
11.2. Sound but no picture, and backlight not illuminated
Even though LVDS data is printed on the screen, the picture cannot be seen
because the backlight is not illuminated. First, cable connections, particularly inverter
and supply cables and connectors should be checked.
24V power supply should be checked over inverter cable when TV is ON. When this
power needs to be supplied to the inverter unit of the panel, the backlight will not be
illuminated if there is not 24V supply. 24V and 12V supplies are switched on by
POWER_SW signal coming from the main integrated circuit when TV is ON. In this
case, if there is 12V output but no 24V output, then the problem rests in the power
supply.
If 24V supply exists on the system, a voltage over 3V DC should be transmitted to
the panel on the Leg 5 of S606 connector. This voltage gives “switch on” command
to the panel inverter. This control is provided with “BL_CTRL”.
Besides, voltage level that determines brightness of panel lights through Pin 6 of
connector S605 should be higher than 3V. Brightness control may vary according to
the panel, however, it operates dimly around 0V and completely on around 3.3V.
Brightness control is done by “BRI_ADJ” signal coming from the main integrated
circuit.
When the "backlighting" tab is dimmed in the user menu, the voltage in the Pin 6 of
the connector decreases slowly.
If no problem appears in the checks performed at the chassis, you should consider
that the problem might be arising from panel inverter module or the lights.
11.3. No Sound
In case of sound problem, not only one but also various sources, cables and devices
should be checked against the problem. You need to make sure that volume has not
been turned down from television settings or mute button is not pressed.
If there is not any problems, check the loudspeaker cables and loudspeakers on the
chassis; fix the problem, if any.
Before starting detailed controls, headphone socket should be checked against audio
problem. As an amplifier is used, the headphones output is obtained by amplifying
EAR_OUT_R, and EAR_OUT_L signals which are sent directly by main integrated
circuit through IC500. If you cannot receive audio from headphones socket, those
signals are checked from R500 resistor’s pin 1 and 7. If no signal is observed, then