One thing that may help is a manual. If the set has either a type acceptance
number or an FCC ID number you can look it up at FCC.gov. That
USUALLY will cross it to the OEM & OEM model number. We used to find
near every odd ball monitor that way.
With the OEM someone may remember the problem or get you into the
service menus. Maybe a "so called" manual too !
BTW those menus if used wrong can destroy some sets. ALWAYS write
down all parameters before changing
73 Zeno
LFOD !