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Chapter 5: Troubleshooting
5. Troubleshooting
5.1 Problems/Solutions
Problem:
Fuzzy, blurry, or ghosting image at remote location.
Solution:
If you have a stable image but it looks somewhat blurry, make sure you
have adjusted the receiver unit’s compensation correctly (see Section 4.2). Also
check Table 4-1 to make sure that you have not exceeded the maximum cable
length recommendation. If you still have a fuzzy image, try reducing the refresh rate
and/or resolution of the PC.
Problem:
Image exhibits steady or rolling horizontal color “hum” bars.
Solution:
This is usually an indication of improper grounding either at the sending
end, the receiving end, or both. Verify that the AC line is properly wired and that a
protective ground (green) wire is established with NO potential difference between
both the sender and receiver locations. The UTP splitter can tolerate up to 5 v peak-
to-peak ground noise between the two locations, but no more.
Problem:
Shaking image or periodically blanking monitor.
Solution:
Although CAT5 cable uses twisted pairs to transmit the signals from the
splitter to the receivers to reduce the amount of EMI coupled noise from other
external sources, a strong electromagnetic noise field can cause instability in the
signal.
Usual sources of this form of noise coupling are high-current AC lines or other high-
density data and/or control cables that run adjacent to and parallel with a substan-
tial length of the CAT5 cable. To eliminate this, either place the CAT5 cables further
from the interfering source, or use STP shielded CAT5 cables.
Problem:
The PC does not recognize a plug-and-play monitor.
Solution:
If the PC’s operating system is setup to detect a plug-and-play monitor
(usually in Display Properties Advanced Settings), it may have trouble finding a
monitor if no local monitor is attached to the splitter (at the sending end). Only the
ID information of the local monitor is passed to the PC. If the PC does not produce
an image because of this, either connect a monitor to the local VGA output port,
or disable the plug-and-play monitor detection in the PC’s operating system.
