Troubleshooting
91369 Service Manual
5-18
External Display
1 Check the external display’s power and video cables for proper connections. Verify that the display
assembly is set in the correct operating mode.
2 Verify that the external display’s brightness, vertical, and horizontal sync are set correctly.
3 Verify that the external display’s terminations are set for 75 ohms, if settable.
4 Run the Video Diagnostic (refer to
on page 5-8). If it fails, replace the CPU
PCBA.
5 Inspect the Interconnect PCBA and I/O PCBA. If any connectors or parts on either of these assemblies
appear damaged, replace the damaged assembly.
Keyboard, Mouse, or Barcode Scanner
1 Try a known good USB mouse or keyboard (there is no setup for the mouse or keyboard, either externally
or internally). Cycle the power OFF and ON after changing the keyboard or mouse to guarantee that they
are seen by the monitor.
2 Check the USB connector for damage, and replace the damaged assembly if necessary.
3 Try a known good USB mouse in all the USB ports. If none work, replace the CPU PCBA.
Barcode Scanner
Ensure the barcode scanner is set for keyboard entry mode.
Battery
The monitor can assist in troubleshooting failed batteries in several ways. It can detect gross failures such as
shorted and weak batteries and batteries that cannot hold a charge. It cannot detect all battery failure modes.
To debug a problem battery, run the following tests.
Battery Charging Test
1 Install one or two suspect batteries.
2 Power the monitor from the AC power supply and switch the monitor OFF. The front panel battery LED(s)
will be ON or blinking.
3 Let the batteries cycle through a complete charge. For batteries that are initially charged, wait at least one
hour and 40 minutes. For batteries that are initially uncharged, wait at least three hours.
4 Check the front panel battery LED(s). If a faulty battery is detected, the front panel LED(s) blinks ON and
OFF at a rate of 500 ms.
5 Replace the bad battery or batteries.
Battery Fuel Gauge
When the monitor is powered by batteries only, with one or two batteries installed, a battery fuel gauge is
displayed in the lower right corner of the screen. This gauge is useful in detecting bad batteries or other voltage
problems in the system. After five minutes of operation on only one fully charged battery, if the battery fuel
gauge reads 3/4 full or less, the battery may be faulty.
