I checked my repair data base and found the following similar problem.
The problem That we had was just opposite of your description. The T-CON
board was the problem. The t-Con could cause problems on either side.
Left Half Of Picture Green - Right Half Perfect, Replace the Timing Control (AKA -Signal ctrl/T-con).
Signal ctrl/T-con board.
You would need a trained technician to check and change the change the board.
I had rather have a happy non paying customer, than a paying unhappy customer.
Good luck !
I don't have any other suggestions. I have opt out to let other experts try and help.