Original post by: jayeff ,
Hi, Given that the phone has been dropped I’m guessing that the problem is in the screen assembly. There are delicate internal connections in an assembly that may have been damaged and this may not be evident from the outside. As a DIY repair all you can do is to open the phone and first check that the display assembly flex cable is securely connected to the systemboard. If it is then after that you have to temporarily replace the screen assembly to find out whether the problem is in the assembly or the systemboard. Here’s the ifixit [guide|136889] guide which will help. Replacement screens are available online. Just search for ''Galaxy S10 Plus LCD Touch screen assembly'' to find suppliers that suit you. If doing this yourself seems too daunting, contact a reputable, professional mobile phone repair service and ask for a quote to repair the phone.