GLad someone got to trouble shooting.

If the fuse was gone - no deck operations at all.

I'd, assuming detachable face deck, would take either an eraser or even better isopropyl alcohol and cotton bud and clean the contact between the face and the installed head unit. If corrosion is large some 400 sand paper will suffice.

Always try to find a solution before throwing and buying. Quite often the components in an older head unit will be better than the "made to a $" parts of today.