Thank you for the reply.
The problem is indeed the power supply output that drives the Inverters which light the LCD panel. The frequency of the blinking is due to the supply oscillating and not being able to supply the voltage to these Inverters, and the supply should be replaced. The link below is where you can purchase the power supply board for your TV to fix the problem:
That one is actually showing as out of stock, and actually all of the vendors I've checked are no longer showing new, used, or pulled power supplies for this TV as available. You may need to get the supply you have serviced as these parts are scarce to not- available for your TV. If you'd like to do this, you can use the link below to locate a TV repair shop to repair the supply board:
Another option is to keep in contact with: www.shopjimmy.com as they are a pulled parts supplier and are the best at locating hard to find boards. They are currently showing out of stock on about all of the boards for this TV currently, but if you have them put you on their list, they will contact you once a board becomes available:
The last resort, would be to scour www.ebay.com with the model number of your TV and the keyword "power supply" to try and find a used board.
I wish I had better news, but because the problem is so common, the supply board is scarce to not available at this point in time.