MERIT INDUSTRIES Megatouch XL Technical Service Reference Manual page 17

Problem 1 The touchscreen appears to lose calibration if you touch the screen while
touching the metal on the cabinet (this particular problem is most likely to affect
upright and cabaret games, not countertops).
Solution Make sure the controller and/or the cabinet is properly grounded. NOTE: For the
19" upright, you may have to remove the paint from the hinge that the ground
braid is attached to in order to get a better connection.
Problem 2 The touchscreen won't calibrate correctly. This is a vague problem that requires
more information to determine the cause. To investigate further, go to the TEST
SCREEN mode and slowly pull your finger down the screen in a vertical line.
A) If the crosshair moves in a wavy line (sine wave) then there is a bad EEPROM in
the Microtouch touchscreen cable connector.
Solution Replace the touchscreen glass. NOTE: TO PRESERVE THE VALIDITY OF
YOUR WARRANTY, CONTACT MERIT TECHNICAL SERVICE (at 1-800-445-
9353) BEFORE ATTEMPTING ANY SERVICING.
B) If the cursor generally follows your finger, except for one particular area on the
screen, the EEPROM is not correcting for flaws in the touchscreen glass.
Solution Repair or replace the touchscreen glass (or you can try switching touchscreen
controllers, if you have another one. This can cause the EEROM to reinitialize
itself, leaving you with both controllers working).
C) If the crosshair moves continually towards one of the corners (the same corner
each time), every time you run your finger down the screen, the touchscreen
glass has a broken wire.
Solution Return the glass to Merit Technical Service to have it fixed.
D) If the controller works for a while, but stops working (the TTL LED does not
respond to a touch), the controller may not be properly grounded.
Solution Install the TTL Ground/Static kit (#SA1089-01) and the CRT-266 Electro-Static
Discharge Board kit (SA1088-01). On the upright model, you may want to check
the gray and green wires from the touchscreen controller cable. They should be
attached to the ground on the power supply.
Troubleshooting Your Touchscreen