The Master Massage Thermal Top Tables includes a controller that controls temperature and duration of the heat. It is often a white controller with a light grey (almost white) back and comes with a cable attachment to plug into the wall on one end and a cable attachment to plug into the table on the other end.
Sometimes when the controller stops turning on, a replacement can help with the issue. Replacement controllers can be purchased directly from our website:
https://www.mastermassage.com/products/cord-with-controller-for-therma-top-table?_pos=16&_sid=6d2527d06&_ss=r
To replacement the controller, you would need to lay the folded table surface on the floor, preferably allowing the side with the controller attached to touch the surface of the floor. Then you open the table and prop the leg of the opposite end onto the wooden surface (wooden surface of the part that has the controller attached). It'll allow easier access to remove and replace the controller.
Many struggle to remove the controller; you would need to press down into the two square holes of the cord that connects into the table and then pull to remove. You could use 2 screwdrivers or scissors to do this simultaneously. Here's a video demonstration for your reference.
https://www.dropbox.com/scl/fi/hfwl21mg7qnwr6lggpjth/remove-TT-controller.mp4?rlkey=ddux3b5iplau75lg6uqb58rsv&dl=0