has a lot of people with similar lines.
Seems related to flashing certain roms and overheating issues.
Most likely you now have a bum screen and need to send it in for repair.
HTC Dream - CM 4.2.11 - Retired, fried something by being an idiot and trying to OC to 712 Mhz.
iPhone 4 (found on a park bench) - tweaked to the gills - Eventually donated to my mum after I got my Galaxy S3
Samsung Galaxy S3 - Carbonrom - Stolen at concert
LG Optimus 4x HD - Vanir - Gave to girlfriend with a clean/stable install of CM 10.2
LG G2 - Today, CM11, tomorrow, who knows?