Question Panasonic 4 blink code TX-37LXD85

[roders5]

My Panasonic TX-37LXD85 has a 4 blink code. I am understanding that this is an overvoltage of the 3.3v line.

Can you assist in what components on P board or A board may be at fault?

I have the service manual so can identify the components and locations.

I would also like help in testing components whether the boards should be connected or disconnected

 

[roders5]

Ok if nobody can help with the fault. Can someone explain the wireing diagram.
The diagram curcuit is colour coded with Green Red blue and yellow. Can anyone explain the colour designations.