If the unit works/boots/displays correctly on another display, I would check/change settings for that HDMI input on your plasma display. Best advice I can give otherwise is to remove power from the Android device then power up the plasma, then switch to that HDMI input, then apply power to the Android device. If it still does not display, you may have a bricked unit and should return. Amazon returns are generally easy. Should be especially easy for this device as there seems to be a large number that are dead on arrival.
Have to ask a dumb question but is the power mini-USB connected to a 5v source ? If so there will be a blue light on the side of the MK-802 below the full sized USB connector. If you do get the Android logo than it it needs to be reloaded. The "instruction manual" says it can be downloaded but does not give a URL. (ps Anazon says to contact OEM Products but does not give the right OEM Products