I set up my A1200 tower for the first time in about 3 years yesterday.
After a few moments checking connections (I'd left the power plug out of the back of the MB), I had a moment of happiness when the purple insert disk animation appeared on my CM8833 monitor.
I didn't get to do any more than this, but the 20-year old hardware still seems to work without problems.
I've taken the Hard Disk out so I can now use WinUAE to copy the ClassicWB build I have to it.