Why did my heater stop working? on 1996 Lexus SC400

Well the display has always been dim since the day I got it,but it went out completely won't power on completely dead?

Asked by for the 1996 Lexus SC400
seek a diag and est as to not waste money on guesses
Thanks ;)
1 more answer , 1 more comment
You may have a problem with the heater control head if the entire display will not light up.
Thanks ;)