I was putting my 401a into its new home (cabinet), when it tumbled out of my hands and fell over backwards to the carpeted floor. The only thing I can tell is not working is the back dial stack. This may be due to operator error as much as the fall. Is this something I can open the machine up and check out or do I need to take it to my local repair man? What do you think? Do I dare turn it on before checking it out?