I bought a 3.2" touchscreen from Osoyoo and a friend also bought a 3.2" touchscreen but I'm not sure of the brand. Using it with a Mega 2560 and display shield. Both of us have the same problem. Every now & then after powering up the screen will not respond to touch. A power cycle or 2 (or 3) will usually fix it. Anybody know why this happens and if it can be fixed?
The display shows what it should, just the touch is a problem.
Does your screen need to be calibrated? Dronebotworkshop has a calibration sketch.
It was calibrated but I don’t remember where the sketch came from. Possibly rinkydinkelectronics.
A 9v wall wart for the Mega and a display shield which, I believe, supplies 3.3v for the display.
Hi, @ard_nov
Does the display shield accept 9V?
Can you please post a link to data/specs of the display you are using?
Thanks.. Tom.. 
I’ll have to do that tomorrow (assuming I can find it).
Not sure this will be much help.
The shield has a 3.3v regulator on it and 5 (what I believe are) level shifters.
The screen basically works most of the time. Just occasionally doesn't respond to touch.
Hi, @ard_nov
The 3V3 regulator may be shutting down due to thermal overload.
Try 5V instead of the 9V, the power dissipation in the 3V3 regulator will be lower.
Tom...
I have powered it with just the USB cable (which is 5v) and it still did it. The touch problem doesn't appear after a while, it's immediately after the program is loaded.