Hi and welcome to the site, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, it would appear to be an internal hardware issue. If so, are you then considering a DIY (do-it-yourself) repair approach?
If yes, do you have access to and familiar with a multi-meter?
The only preliminary test that can be done would be to check and ensure that the red wires in the junction box are not shorted or the hi/low or on/off switch these wires connect to have not failed.