Hello there! Welcome to the forum!
Is this your unit?
http://www.rcacommercialtv.com/wp-content/uploads/RCA_BE_Specs.pdf
You should be able to push the input button and change to HDMI.
Can you take a picture of the buttons panel and post?
Is this your unit?
http://www.rcacommercialtv.com/wp-content/uploads/RCA_BE_Specs.pdf
You should be able to push the input button and change to HDMI.
Can you take a picture of the buttons panel and post?