Service manual

Neurodiagnostic Instruments Service Manual
6-22 Revised 2/18/05
Computer Problems
Base Unit blows fuses
Before you attach a laptop computer’s power adapter to
the base unit, make sure the laptop’s batteries are fully
charged. The laptop may draw enough current to blow
the fuses on the base unit.
Boot problems
Determine where in the boot process the system fails.
1. Have you just worked on the system? For desktop
systems, recheck the orientation and security of all
internal cable connections. Verify all boards are
correctly placed and firmly seated.
2. Have you just added new hardware or software, If
so, try restoring XP to an earlier restore point.
3. Does the POST (Power On Self Test) complete?
Does it issue a beep code or display an error
message on the screen?
4. Check the CMOS settings to verify the factory-
default settings have not been modified accidently.
5. Do the fans and indicator lights turn on when you
power on the system? If not, check the following:
- Verify a good source of a.c. power and that the
power cord is functional and securely connected.
- Measure the power supply voltages at the
motherboard.
- For desktop systems, remove all expansion cards
and disconnect the drives, leaving only the monitor
and keyboard attached. Does the system start up
with this minimal configuration? If not, replace the
power supply.
- If yes, connect the drives and replace the
expansion cards one-by-one until you determine
which part may be causing the power supply to fail.
NOTE: For earlier VIASYS instruments, we
recommended the use of the #1TuffTest
floppy-based diagnostic to check
motherboard integrity. The BIS (Boot
Integrity Service) feature of many newer
motherboards does not allow the system to
load non-standard operating systems or files
during the boot process. Since TuffTest is
written in machine code, and is independent
of any operating system, it may not be useful
for testing newer platforms.
Slow operation (VikingQuest)
If you replace printers and install a new printer driver on
the system, the waveform data displayed on the screen
may become very slow. The QMUP test displays a
slow-moving flat dashed data line. To resolve this issue,
you have to uninstall the printer driver, reinstall the
printer driver, then reload the Master Software, in that
order. Refer to Chapter 3: Printers/Printer Drivers for
detailed information.
Display Problems
No display for desktop-based systems
Make sure the monitor is turned on (switch is on the
front or the side of the monitor) and plugged into the
video connector at the back of the computer. Verify the
green power indicator light is on. Reseat the monitor
power cable.
The brightness and/or contrast controls on your monitor
Verify the isolation power supply and computer power
switches are turned on.
Check the video cable for bent or pushed-in pins.
No display for laptop systems
Press the Space Bar to "wake up" the computer. Press
the Purple button to return the laptop from the
"Hibernate" mode.
Slide the laptop power switch off, then on again to
reboot the system.