Panasonic TC-L42D2 Technical Manual page 45

Troubleshooting TCON Problems Continued
Troubleshooting a dead TCON board
When the TCON board completely fails, data communication data between IC8001 and the TCON IC
will come to an end. The television will shut down and the power LED will blink 9 times, indicating the
failure of the TCON.
When there is no error code, the usual approach is for the technician to replace the A-board. Once it
is determined that the A board is not the fix, one can conclude with a degree of certainty that the
problem is the TCON board.
Avoiding wrong board replacement
One way to determine the location of the fault is
to loosen the LVDS connector at the TCON
board while the unit is turned on. Unlock the
connector and gently rock the cable in and out of
the socket while observing the screen for any
sign of noise. The response may be gentle white
flashes, intermittent colored lines, or a screen full
of random patterns. A TCON board that has
completely failed will not generate any type of
symptom on the screen.
Another method to rapidly diagnose the TCON is
to apply heat and/or cool with hot air devices or
circuit coolant and watch for random noise to
appear on the screen.
TC05
A21
LVDS
CONNECTOR
Slide # 45