Samsung LN32B530P7F display flashing on/off

Samsung LN32B530P7F was left plugged directly in the wall by guests. Returned to find the tv responsive to input but nothing on display. Ordered and replaced the power board (entirely scorched) BN44-00261A. New board listed as compatible with BN44-00260/1 A/B/C.

After replacement, TV display comes on and all functions appear normal (renders HDMI signal, plays audio, responds to input/channel/volume/etc), but flashes off and on 3 times before the display shuts off entirely. The TV is still on and responsive while the display is off, and remembers all config changes.

Following other advice, power drained the unit (unplug, hold power, replug), and it automatically turned itself on, the power LED blinked twice before the screen came on doing the same thing again (on/off 3 times). The suggestion there is the main board.

Noticed that not all HDMI ports worked ok, so suspect lightning damage there too. Ordered a replacement BN41-01181A. Fingers crossed.

Anyone else observed this kind of behaviour? Was it limited to the main and power boards?