Panasonic TC-L42D2 Technical Manual page 88

Conclusion: Exchange the A board
Source Driver
LCD Panel (Gate Driver is in Panel)
Diagnosis
Strange color or discolor is A board defect, mainly IC8001 Nile-TCON.
So, exchange the A board.
Picture Defect (8) (D Series)
Gate
Driver
LVDS DATA
Control DATA
TC board
LVDS DATA
A board
(LVDS= Low Voltage Differential Signaling)
Sample Picture
Strange color
Strange color part
Slide # 88