Transistors in general, tend to fail shorted- hence full output. This being an AC device, specific subset of transistor type TRIAC or Thyristor.
I comes down to this simple fact: these have a microprocessor as the heart of the unit. If that fails- you cannot get that part or more specifically a programmed processor making the unit unrepairable. This is often displayed by lack of a green LED power indicator since that is off a processor pin. But key is, the symptom is no light, fan can be heard or felt (airflow) running (so we know fuse is good). Outputs either could be stuck on or blown so badly no output. https://ogrforum.com/...2#159660139144800982
Again, the hope is, you have a green LED, and stuck on ouptuts= most likely blown output TRIACS stuck on. Now if they damaged anything else is a bit of a shooting match.
Schematic thanks to @gunrunnerjohn
https://ogrforum.com/...2#155716354824086312
Security screw discussion https://ogrforum.com/...80-disassembly-tools
