Black LCD screen, but:
external monitor works, and
all diagnostics (BIST, F12 diagnostics at boot) show the display is fine.
Drivers are up to date.
I'm out of ideas.
I appreciate you have tried few steps to resolve the issue; since the external display works fine I suspect an issue with video card.
Depending on the warranty status we can help you further, please use the link below to check the warranty status.
Please punch in the system service tag or express service code. In case your system warranty has expired please contact the Out of Warranty department 1-800-288-4410 (U.S.Customer only). In case your system is under warranty please send me the system service tag or express service code through a private chat, so that I can help you further.
Click on my username select start conversation and send me the details.
I am glad to hear that the issue is resolved, in case you have any issues in future please post it in this link or start a new thread.