Can't turn the unit on or off with the power button?

Part no: ECH1500IPHB-BNC - Case 6-OW-109762. Question: Can't turn the unit on or off with the power button?

Question:
When I give my display power I can see it come on. ( it flashes to a dark black). The yellow light comes on on the side. But does not go past that. I cannot turn the unit on or off with the power button.

Answer:
By the description on failure symptom, seems backlight or AD board issue. Please help to confirm following:
Is it really no any response on power button, to turn off or turn on the light (orange or green) of indicator on side OSD?

It may require waiting more than 5 seconds the interval to turn off or on the light of indicator. If AD board is in good condition, power button can turn on or off the indicator.

The indicator will turn green when active input signal is on, but this composite 3D-SNR AD board is not auto-searching type, require manually select by AUTO and UP buttons to select specific one (PC-VGA, HDMI or AV) on pop-up menu. Any input can let it green means the board is in good condition.