KVM Video problems

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Mike

Hello, I recently purchased a Belkin Omni-view PRO 4-port and I'm
having problems running 1280x1024 @ 85hz. I see these small vertical
lines on my monitor spaced about 1/2" from each other. When I reduce
the resolution, it helps. I also notice that icon text is a little
fuzzy (seems like crispness is comprimised).

The cables I'm using are NTW 6' (part # 141M-0634MF/F with ferrite
cores). I would imagine these are sufficient enough.

I am convinced that there's something wrong with the KVM switch. The
cable from the KVM to monitor is of the same characteristic (ferrite
cores, 6') and I don't have problems when it's directly connected.

Will image quality be *that* crappy when the cable length is doubled?
Is it possible to test the signal before and after the KVM switch? It
seems to me the KVM is putting noise on the cables, which may explain
the evenly spaced lines.

Thanks.
 
Mike said:
Hello, I recently purchased a Belkin Omni-view PRO 4-port and I'm
having problems running 1280x1024 @ 85hz. I see these small vertical
lines on my monitor spaced about 1/2" from each other. When I reduce
the resolution, it helps. I also notice that icon text is a little
fuzzy (seems like crispness is comprimised).

The cables I'm using are NTW 6' (part # 141M-0634MF/F with ferrite
cores). I would imagine these are sufficient enough.

I am convinced that there's something wrong with the KVM switch. The
cable from the KVM to monitor is of the same characteristic (ferrite
cores, 6') and I don't have problems when it's directly connected.

Will image quality be *that* crappy when the cable length is doubled?
Is it possible to test the signal before and after the KVM switch? It
seems to me the KVM is putting noise on the cables, which may explain
the evenly spaced lines.

Thanks.
Click to expand...

The increase in cable length can affect video performance. Some video
cards simply don't provide enough juice to overcome the increased
attenuation of not only adding more cable but also of adding the KVM
unit. You mention the part # for your cable set but I found no such
part number on the Omniview KVM Cable link (http://tinyurl.com/htn2) on
the Belkin's KVM page (http://tinyurl.com/4vmv). They only list their
model numbers, not their part numbers, so I don't which cable set you
have. The added fuzziness would be attributed to attenuation due to the
longer signal path. Their product web page for the Omniview Pro says it
will support up to 1600x1200 at 65Hz refresh rate. Their manual at
http://tinyurl.com/htnz has no detailed specification chart to specify
what refresh rates it will support at other video resolutions. Perhaps
this KVM will not support 85 Hz at 1280x1024, so reduce it to 75 or 72
Hz to see if there is any improvement.

The horizontal lines are probably from some EMF interference. Move
everything away from your monitor, like computers (since these are
B-rated for EMF, not A-rated), printers, speakers, and even the KVM
itself (since it has a power supply). It could be that your monitor
just isn't up to shielding out all the EMF near it. The cables of many
monitors isn't that great, either, so if it is detachable from the
monitor then you might consider replacing it with a better one.
 
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