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TP CHASSIS / TELEVISION
11. FAILURE/ERROR CODES
11.1. Sound but no picture, and backlight illuminated
In this section, we will basically explain where we need to check if there is "no picture
on TV" even though there are not any problems in the panel inverter. Here, we are
assuming that chassis is generally in good condition as we obtain sound output from
TV. When you cannot determine if the backlight is working or not due to the
illumination level in the environment, you are recommended to tap on the TV's front
panel lightly; if the backlight is working, you will notice a slight glowing.
Before starting controls and repairs, it is crucial to analyse and comprehend the
problem exactly. In this problem, you must make sure if it is originated from the
utilized source, if it is a cable connection error or if utilized devices have any
problems or not.
Then, particularly LVDS cable on the chassis should be checked for any
disconnections, loose parts, dislocations, breaks or ruptures. Likewise, it will be
proper to check cable connections of the panel.
Later, the panel power (VCC_PANEL) supplied to the panel T-CON board over LVDS
cable should be checked on L615 position in the chassis. Panel supply for the
products with TP chassis is 12V.
If this supply is not available on L615, check for 12V on the S605 socket's pin 11. If
12V supply is not found on S605 socket although POWER_SW signal exists, PSU
should be replaced. If POWER_SW signal is not available, main IC and peripheral
components should be checked.
If VCC_PANEL voltage is found in T603 Leg 2 but not found in Leg 3;
T603 and peripheral components are checked. When TV is "ON", a voltage around
3.8V occurs on Leg 1 of FET as to be higher than 0V, and supply voltage on Leg 2 is
transferred to Leg 3. If Leg 1 does not have voltage, check "TCON_ON" signal on
Leg 8 of R660 resistance. Here, if the voltage is High, it means that panel supply has
not been turned on from the main integrated circuit or software. This signal remains
high while the TV is going out of Stand-By and gets down to 0V, 1 seconds before
the picture appears on the screen.
If the panel is supplied voltage over LVDS, it is most likely that picture information is
transmitted as well. Even it is not a precise control method to be used during
information flow over data lines, the measuring tool detects voltage around 12V DC.
In this case, an error is likely to be found in panel side or 100Hz URSA processor,
RAM or flash.
If LVDS supplies do not have a problem and LVDS data reaches but does not exit
IC800, URSA should be checked. URSA processor IC800 and RAM's IC801
VCC1V5 supply voltage should be checked. Also, the error may be originated from
IC802 URSA flash or software (URSA.bin).
84
September 2011
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