Relays clicking, the sound of motors whirring (that’s the doors), and a final relay clack are all good signs when power is applied. Next is basic CPU working at all, and ribbon cables connected, so: Does the little red dot in the upper right display show up? Do any of the buttons work? I.e. “Load Tape” & “Load CD” ought to whir the motors even if the doors are frozen shut. And “Sound” button ought to make the upper display show “Volume” and lower display show arrows lower left. Any of that? This much functionality is required before playing or amplifying anything. I don’t know enough to walk you all the way thru, but “does not work” is pretty broad. So maybe with these three answers or a few more details, others with more experience can make good guesses…