HP G4 laptop, horizontal dashed line across screen.

Which HP G4? Please finish the model number. It's an HP G4-xxxx dx/nr/whatever.

The G4-XXXX whatever is a fairly new laptop. I suggest you check your warranty status before attempting a repair.

Probably a faulty LCD panel. Usually, the line is white, not black. White usually indicates that one of the flat ribbon cable connections, that surround the edge of the LCD panel, has gone open. Black usually indicates that the driver chips is blown, or that there's a short to ground. I see lots of white lines, but very few black.

You can sometimes get lucky if you open the display section, and massage the flat ribbon connections. They're located under the label that says "Don't touch this or you'll trash the LCD panel". Ignore the label.

Here's a repair method that I don't really recommend unless you're desperate:

Hi Jeff,

I will be in touch with the owner this weekend and be able to get the full model number.

Also, I think I will hold off with the hammer-to-the-display quick fix for now. :-)

Thanks for your reply.

Hi Jeff,

The model number is HP4-1315dx. With that information and the serial number I as able to find out that is in warranty. So we'll have to ship it to Tennessee with about a 2 week turnaround for service.

Thanks for your reply.