presario v6000 display problem

When I replaced a cracked display I wrongly routed the wire under the
hinge and after some time it shortened and melted. The screen got
black. The laptop still worked fine with external monitor. I replaced
the burnt wire but the screen was still dead. Evidently, the graphics
chip is still alive. What else could be damaged? Is there any way to
troubleshoot except replacing with known working parts?

Thank you in advance,
Lenja