Cabling Systems & Solutions UTP = Unshielded Twisted Pair
Rev092007 VG01
Troubleshooting at picture problem:
1. Picture disappear intermittence or no picture display:
Please adjust the Dip switch setting or change the vertical SYNC frequency of the VGA display card, DVR.
2. Display not syncing up properly:
There are some certain models or brands of monitors with very high demand at sync-sensitive and the DIP
switch setting may not compensate properly. Please use STP (shielding twisted pair) cable instead of UTP
(unshielded twisted pair) cable.
3. Blur picture or Loss of image details:
This may occur as the length of twisted pair cable increases, due to the effects of attenuations. Please change
the active type of VGA extender to have a built-in amplifier function to improve the picture, or try to adjust the
contrast and brightness of the monitor. If the application operates adequately at a lower resolution (i.e. 800x
600 instead of 1024 x768), then setting the monitor to a lower resolution will help improve the image. Please
note the higher DIP switch setting for sync compensation may cause more video signal loss or no picture.
4. Flutter:
Flutter occurs when the background fluctuates between light and dark. This status may be caused by the
grounding problem between the VGA equipment or the connection may be picking up some external
interference from a nearby power transformer. To fix this problem, change the cable to an STP cable.
5. Ghosting:
Ghosting is characterized by a second video image being received after the main image, resulting in a double
image. This is usually caused by the UTP cable connection itself, poor crimping, untwisted pairs, some of the
twisted pairs may be longer than others, poor quality cable, or the impendence mismatch of the cable. In these
cases, the best way is to replace the existing cable with a new one.
6. Wrong colors:
If the wrong colors appear in an image (for example: blue appears where green should appear), the problem
may be caused by poor crimp at RJ45 connector or wrong pin connection. Please check all connections and
verify the pin configuration of the cable between CPU and the monitor to ensure that the correct pin
configuration is respected.
Note:
1. The maximum distances supported by the VGA Extender are dependent on the type of twisted pair cable
and image resolution of the PC’s VGAinterface. Make sure that the maximum recommended operational
distances have not been exceeded.
2. All wiring is “straight-through” twisted pair cable, not being used for other LAN or telephone equipment. Do
not connect the VGA Extender to a telecommunication outlet wired to unrelated equipment.
