To check calibration (check only, not do the calibration), press the Battery icon at the top right of the main screen for about 8 seconds until you enter the diagnostic mode. Press the "Next" button to advance 4 screens (maybe more on some models) until you get to a black screen. Touch the screen with a stylus or finger. You should see a blue dot centered on where you touch. If it's not centered, then follow the procedure given by
dvpro to calibrate. Often you'll be centered on only part of the screen (for example the top half but not the bottom half).
After you are done, tap "Next" until you return to the first diagnostic screen, then tap Exit to finish.
This is useful since MFM has so many POIs

that you need to be precise to select the right one.