390X Bad Screen or Bad Connection?

[fwebb]

1) 2626-HOU P3 500mhz (upgraded) 256ram, CD/Floppy combo, onboard ethernet, Win 2000.
Cosmetically the 390X is in very good condition, barely a scratch.
How can you tell whether the screen has gone bad or maybe has a loose connection? Works fine on external monitor. Notebook was shipped from Alaska to me. No evidence of damage, although the shipping box was beat up a bit.
2) On board ethernet not shown in device manager. will not connect to a wired Lan. Wireless card works fine. Driver problem with onboard ethernet?