This issue is widespread on the htc bolt, and few people have found ways to fix it. One of which shows up if you Google search this exactly, "htc bolt half black screen" . If you search that the 5th search result is "Solved: HTC Bolt Display Screen Half Black Broken"
The link is this:
But for some reason the link doesnt work and I cant find the post anywhere
I found this YouTube video but it's in another language and I cant figure out what he's doing
Does anyone know how to fix this issue? Or have a working link