IBM 4820 System Reference Manual page 102

Troubleshooting common problems
Condition description
Touch display not responding to touch
Totally blank display
Incorrectly displayed data
B-2
4820 SurePoint Solution System Reference
Resolution
v Make sure that only a finger is used to touch
the screen.
Note: The sensor can only detect fingers. Do
not use pens or pencils on the touch display.
v Check to ensure that the keypad/MSR/touch
cable is correctly attached to the 4820 display
and to the 4694 system.
v Run the service diagnostic diskette.
v For model 48T, refer to "Locating the
touchscreen controller information" on page
11-1
v Check the cable connections and replace the
cables, if necessary.
v Replace the 4820 display.
v Check that the power indicator for the display
is ON. If not, go to the first condition listed in
this table.
v Check that the system unit is ON.
v Check the brightness controls.
v If LED is orange (amber), go to the second
condition listed in this table.
v For models 46x, 42x, and 4Fx, run the
service diskette.
v Check the cable connections, and replace the
cables, if necessary.
v Replace the 4820 display, if necessary.
v Check to ensure that the cables are securely
connected.
v Run the 4820 Video Quality Test Pattern.
v If necessary, replace the cables.
v For models 46x, 42x, and 4Fx, use the
service diskette and run the display test for
your host system. If the test is successful, the
application software can be failing.
v For models 48D, 48T, run the IBM POS
Device Diagnostics, which came with the
POSS for Windows installation.
v Replace the 4820 display, if necessary.