I had the same problem with a Panasonic Viera Plasma TC-P50S3 with 14 flashes. I used an ohm meter tocheck
continuity of the boards inside, starting with the power board (power to TV off). Check
YouTube for videos on how to do this. The SC card showed a fault (It was reading close to zero ohms on both pins. I could find no one who supplied SC boards and could only find repair kits. Repairing a circuit board is outside of my ability, time and tools. I found a place online to send the SC board in for repairs. $65 plus shipping. I was getting $350 "ballpark" quotes from Panasonic authorized TV repair shops. If none of this works for you, there are TV salvage companies who will pay
you some cash
and pick up TV from you. You can also sell it on craigslist for salvage parts or part it out separately. The various boards seem to cost around $100 each and you likely have four or five in your TV. At least for my TV, the parts don't seem to be out there, so there is a demand for the salvageable parts.