As an update I left the MODX on for around 8 hours yesterday after a touch screen recalibration and it was working normally at the end of that time. I'll keep an eye on it and see if it changes over time.

Back again with touchscreen problems! The MODX7 hasn't been used for 2 days and the screen was in calibration when last I shut it off. First power up of the day and, as before, I need to touch well below the actual "button" to get it to respond. Screen calibration routine doesn't work: the top two squares go OK but when trying to touch the lower right square nothing happens (or the touch point is somewhere below the screen area). I guess it's time for a trip to my friendly Yamaha service center!!

Not quite yet. You are misunderstanding the calibration routine. It is designed to restore the accuracy of the touch points. The idea is to tap the white pixels - get it to respond. That should straighten out the screen accuracy. If you are looking for a cause, well, that I’m sure is different from what you can determine from the information provided by the recalibration routine. The calibration routine only fixes the screen accuracy when it is obviously off axis. If way off when touching the lower right one, run it again, immediately... it should improve.

How is it is immediately following the calibration? — that’s what you want to be concerned with. If after running the calibration, the screen remains off kilter then seek repair. It may indeed be an issue, particularly if this happens often. I am not sure how/if the length of time a product is on or off affects the accuracy of the screen... it’s more likely something physical. Either way, it just might be time for authorized service.

Thanks for the response but tapping the white pixels to get them to respond is the problem. The top two squares respond but the next one in the lower right doesn't respond to either tapping directly on it or anywhere around it. The calibration can't proceed if the lower right touch point doesn't respond. As an example this morning, when I went to the utility screen to access settings and I pressed the "System" button the "Advanced" button highlighted and that page opened. I had to press in the space well below "system" to access that page. Since touchscreens are sometimes bothered by temperature or humidity changes I put the MODX out on the porch for 15 minutes: it's been cold (40's today, that's relatively cold here in New Orleans!) and the heat has been on (68 degrees F inside). Now that the display is cooler (to the touch) I can complete the calibration, so it may be temperature related (the MODX wasn't near a heat source or in sunlight inside but cooling it off seemed to work). It's working and I'll keep researching the problem if it occurs again. (And on a side note: I was listening to an old album last week by a group called Tarika Blue. Good keyboard player: wonder where he is now!)