It had quit some time in the eighties and was found by my dad a few years ago when he cleaned out his storage shed. My brother brought it back to our place. After a lot of searching on the net we found this page which enabled us to diagnose the main problem. (a bad video interface chip) We Found an new-old-stock one online for $24.00. Fortunately it just plugs into the motherboard without soldering. After replacing the audio/video cable and power supply plug, we got it back up 100%! The tape drive and game carts all work too.
We also got set up to download new software for it which we can upload via audio cassette.
This was only possible thanks to the Commodore fans having archived a lot of useful info for many years.