Micros Systems Workstation 4 LX Service Manual page 103

• The touchscreen extension cable is defective. For example, one pin of the original
extension cable is pushed out of the connector body and not making contact. On
the newer style extension cable, make sure the cable does nor have very sharp
bends.
• Defective Touchscreen Glass.
25-Point Calibration Issues
The 3M Touchscreen Calibration Utility offers a 25-point linearization utility in
addition to the 2-point utility. On units running the GR 1.0 or GR 1.1 software
platform, the 25-point utility can, on some workstations, crash and render the
touchscreen unusable.
• Field Bulletin FB04-003 addresses this issue by connecting a mouse and using the
2-point calibration utility to restore touchscreen operation. GR 1.2 or later
includes an improved 25-point linearization utility.
False Touches
Symptoms: The cursor may jump to random locations or to the same location without
touching the screen. The cursor may also jump to a different location than where you
touch.
• Defective Touchscreen Glass.
Examine the touchscreen surface. Look for obvious gouging caused by objects
dropped on the screen. If there are no obvious defects on the touchscreen surface,
the touchscreen is failing, and it may eventually fail completely, causing a POST
error. This is more likely to occur on the first 3800 workstations produced. Refer
to FB04-004 to see if the touchscreen is covered under the replacement program
detailed in that document.
Workstation 4 and 4 LX Field Service Guide
WS4 Troubleshooting
Touchscreen Related
3-17