Hi @cuzz
According to p.94 of the [https://www.photo-manuals.com/manual/minolta/film-slr-camera/maxxum-7xi|user manual], ''help'' indicates a winding motor problem.
The solution offered is to remove the battery and then re-install it.
What is the battery charge being shown by the 4 bar indicator in the data panel when you turn the camera on?
Just verifying that you installed a 2CR5 Lithium battery? Maybe check the voltage of the battery. It should be 6V. The shutter is locked when the battery has been depleted.