Ihave a insignia ns-lcd47hd-09 tv. when i press the power button the light turns blue but no picture comes on only black screen.

I think your insignia is set for SHOP mode instead of HOME mode. I changed mine to HOME and it's working fine now. Press your menu button and then scroll down to setup. You're looking for Plug and PLay which should be the very first choice. If it's greyed out as mine was you'll have to change your imput from HDMI to TV in order to get to the P&P. Once you're in the Plug and Play your first choice is language. The second should be SHOP or HOME. Make sure to select HOME. You can skip scanning for channels. This fixed my problem with the blue light. The store uses SHOP so if someone plays around and changes something, all they have to do is shut off the TV and turn it back on. Please let me know if this works.