The constant flashing LED on the logic board is normal on an operating Samsung plasma. You're looking at a faulty connector between the display panel and the buffer strips along the bottom of the panel, situated directly behind the vertical line. These connectors are fused into the panel glass at one end and probably glued to the pcb strip at the other end and may have a driver IC embedded onto the connector cable.
You may be able to effect a repair by using a pressure pad on the strip end if the fault is there, but all other scenarios mean the display panel is knackered. So, removed the metal strip that covers these connectors and check there. Bruce
