Service manual

UCW and Ultraview 1700 Monitors — Service Manual
5-2
Symptoms
Monitor Has No Display
Power
1. Check the AC line cord to ensure that it is properly plugged in and that the power source
voltage is present.
2. Verify that the main AC switch is ON.
3. Check the power LEDs on the CPU assembly by looking through the ventilation holes near
the 10BaseT jack (
) to verify that all four are lit. The LEDs are in a row, deep inside the
case, not near the back panel. They indicate the presence of the +3, +5, +12, and -5 VDC
sources.
4. Check the mains fuses located in the back of the monitor in the AC module.
5. Unplug all the rear panel cables, because a short could cause the power supply to shut
down.
6. Remove the top cover and inspect all cables to verify that none are loose or disconnected.
CPU and I/O Boards
1. Remove the PCBA drawer assembly.
2. Check that the DIMMs and other plug-in devices on the assemblies are fully seated.
3. Reinstall the PCBA drawer assembly.
4. Re-check the monitor to verify that it is still non-operational.
5. At this point, a terminal (or computer with software capable of VT100 emulation) with
settings of 9600 (N, 8, 1) may be required. Connect an appropriately wired cable to the
terminal or computer’s serial port and then to the monitor’s rear panel RS-232 connector
number one. During power-ON, verify that the monitor is passing data to the port and that
self tests are being performed and pass.
6. If the four power LEDs are ON and there is no output from the RS-232 port, replace the CPU
board assembly (refer to
Maintenance on page 4-1).
7. If the RS-232 reports no failures, inspect the interconnect board. If it appears damaged,
order a new I/O board.
8. If there is still no display on the screen, replace the display assembly itself (90385 only).
!
• If an overvoltage condition occurs, the monitor MUST be left in the power OFF
condition for at least 5 minutes before re-applying power.
• To verify if an over-current condition exists, watch the LED’s while turning ON the
power. Check that they do not flash ON and then OFF again.