"LOCKED DOOR" light flashing on my GE oven

"LOCKED DOOR" light flashing continuously. Door lock is open. Oven door will close. SELF CLEAN will not function but asks me to set timer.If I try to set the BAKE or BROIL function a green "door" light comes on. Nothing functions. A service tech came out, looked at the oven and told me he would have to replace the control board at a cost of $450.00 plus the service call. I opted to try fixing this on my own. Can anyone guide me?
GE Model #: JTP15WOW1WW
GE Serial #: LR616360