I have a 5" Touchscreen display from SainSmart, and I can't use the full screen, or even the touch screen. I have done everything that I could find to fix it. I have adjusted the overscan settings, forced the console size to be 800x480, and tried disabling overscan. My current concern is making the screen work, but if anyone knows how to get the touch screen working, I would appreciate it. It is connected by hdmi and the Little pins on the raspberry.
I am using a raspberry pi 3. I used Noobs to set it up.