Scanner printer copiers x 3 (Kempston MK42)

I got four of these from a lady on Freegle some years ago. I kept one which has worked fine ever since. I've just tried plugging them in; the Lexmark one lights up and the carriage moves, the black HP one doesn't seem to do anything, I can't find the power lead for the silver HP one. Maybe someone has a spare power lead or wants to fiddle with them. Take which you like.