Best bet is post the chassis number.
Usually on a small tag May start with screen size the a
letter & some numbers. ex: 19C101-AB. Also big help is
some "nudies" pictures of the chassis. A lot of us can
see a chassis & say what the problem probably is.
I threw away all my NAP manuals but I still got training manuals
& probably SAMS for it. Not free stuff but I can look things up
etc for free.
73 Zeno
LFOD !