User guide

14797 • November 2004 • Troubleshooting
Page 23
TROUBLESHOOTING
Many system troubles are caused by easily-corrected errors, such as poor quality or
missing input or reference signals. Table 9 lists common problems and their solutions in
approximately the most likely order of occurrence. Try troubleshooting the system
yourself, and if you are not successful, call Sigma Electronics Technical Support, as
explained near the front of this manual.
In the event that a problem is caused by a bad circuit board, swapping the bad board
with a replacement circuit board is the quickest solution. If you need to order
replacement boards or other assemblies, call Sigma Electronics Technical Support.
Table 9. System Troubleshooting
SYMPTOM POSSIBLE CAUSES AND SOLUTIONS
System not powering up. Verify that the power cord(s) are plugged into the frame and the AC power
source. Use a voltmeter to verify the presence of power at the AC mains.
Check the DC test points on the front of the Power Supply modules (see Power
Supply Test Points on page 16.)
Check the AC line fuse on the Power Supply module. See Fuse Replacement on
page 22.
One or a few modules not powering
up or not operating properly.
Check that the modules are fully seated in the frame.
Intermittent or missing signal on
outputs.
Check input sources to make sure the signal is in good condition at the point
where it originates.
Check input and output cable continuity while wiggling the cables.
Possible low voltage on Power Supply module. Check Power supply test point
voltages. See Power Supply Test Points on page 16.
Possible bad DA/Processing module. Swap the module with a known good
module.