Emerson's site does not list any 72" TVs. The largest that I see is a 55" model. There are a few common locations for the buttons, though. Some models have the buttons near the center front of the TV. Sometimes these buttons are on the bottom of the bezel. A few models have the buttons on the right hand side of the TV. The Emerson LF501EM4 and LF461EM4 both have the buttons on the lower back of the TV on the right hand side as you face the TV.
If the buttons are in a horizontal line, the power button will be on the far right (when you look at the front of the TV). If the buttons are positioned vertically, the power button will be at the top.
The manuals are available from Emerson Audio Video on the product page or the support page for current models. Start at http://www.emersonaudiovideo.com/
. Funai manufactures the TVs with the Emerson name. For older TV models, try http://www.funai-corp.com/support/manuals.aspx
to find the manual.
WIthout the model number of the TV, I can't give any better information about the location of the front panel control buttons. I hope that your TV has the control buttons in one of the three above locations.