Original post by: Minho ,
Touch Disease does not always exhibit the grey bars. You can check my [https://www.ifixit.com/User/About/1395548/Minho|profile] for a link to a blog post I did a while back. The easiest thing to try would be to put back the original, cracked screen and see if it exhibits the same symptoms. If it does, then you could rule out software issues by doing a DFU (with your friends permission, assuming he/she has a backup). If that doesn't solve it, then you definitely have a logic board issue and that would require a microsoldering repair.