I bought a T12 Pro for its multi module function.   I has worked until I tried to change the splash screen.  I have been using OpenTX companion for images.   When I tried to access the bootloader menu the screen only flashes and goes dark.   The menu has worked in the past.   Radio has not been dropped or mangled.  The power button is flaky and sometimes will not let me start the radio but will eventlually.  Not sure if these are related issues.

When did you buy the transmitter? The power button shouldn't be failing on a newish transmitter. If it is less than a year old I would contact the vendor and file a warranty claim to either get a new replacement or your current one repaired.

I got it from RaceDay Quads and do have a ticket in on it. I will post the results.... I just have not heard of this kind of problem with a TX.