|Hi Randy, as Sluc states, this seems a common problem.|
Problem is many laptop owners are unaware laptops require servicing every so often by removing any dust and fluff build up.
If not done, overheating can occur and a component or components may be cooked causing this problem.
Furthermore , if used as a laptop on one's lap, or other soft surface, this can block the cooling vent(s) - not wise!
When you tried the external monitor, did you then press and hold the FN key, and then press once the EXTERNAL MONITOR function key?
Good Luck - Keep us posted.
message edited by Mike Newcomb