Crazy VGA cable problem. Please help!!

HomeyJay

Active Member
I just got a shiny new media centre PC and spent hours setting it all up with my vids, pix etc. I also bought a nice new HP monitor that runs at 1440 X 900.
It all looked very sexy until I moved all components to where I needed them and then connected the monitor to the PC using a 10m cable.
Having gone from a standard VGA cable to a 10m cable, I was expecting some signal degredation but what I actually got was a total inability to select 1440 X 900 in the graphics settings. All the other settings were there - right up to 2000 X 1600 or something but the one resolution that I wanted (1440 X 900) was gone.

I brought the pc back near the monitor and used the short cable and the correct resolution came back!!

I only have a VGA input on the monitor, no DVI etc!

I really don't have a clue what's going on or what to do. Does anyone have any observations or can anyone help?
 

psikey

Distinguished Member
Assume your using vista.

Vista needs a signal thats carried down the cable to inform other resolutions or it defaults to the standard ones. From what I've read & experienced this signal can degrade over cable lengths over 5m hence no 1440x900.

Some graphics cards allow you to create custom resolutions so try that (and froce the resolution). I also used a software program called Ultramon as my GPU didn't allow custom resolutions with Vista driver.

PM me for more info on Ultramon if necessary.
 

HomeyJay

Active Member
Actually, I'm using XP media centre.
I thought this was what was happening but I can't work out why other higher resolutions are displayed in the list!
 

psikey

Distinguished Member
Higher resolutions would be fine if their standard windows ones, but I've only had this issue with Vista, not XP :confused:
 

HomeyJay

Active Member
I've now isolated this problem to the cable for sure. I have a Dell XPS laptop which is having the same probelm with this resolution and the external monitor when using long cables. The Dell is running Vista Ultimate.
I'll be trying a better cable in a couple of hours so I'll post back!
 

HomeyJay

Active Member
Hopefully sorted!
Most widescreen monitors that use "non standard" resolutions are not natively supported in XP (possibly in Vista too). New HP monitors are DDC enabled and as far as I understand, this tell the OS that the monitor requres a resolution of X by Y for optimum results. DDC data is transmitted via a specific pin on the VGA cable and many cable simply omit this pin or just dont attach it to anything!
The result is that the OS just supplies a list of common resolutions and if your monitor fits one, that's fine, but if it doesn't then you have a display problem!

I've just got a DDC enabled cable and the problem vanished!

If you're buying a new monitor, you should probably make sure that the cable you're using is fully wired and using the DDC pins.

Any corrections are most welcome...
 

psikey

Distinguished Member
Hopefully sorted!
Most widescreen monitors that use "non standard" resolutions are not natively supported in XP (possibly in Vista too). New HP monitors are DDC enabled and as far as I understand, this tell the OS that the monitor requres a resolution of X by Y for optimum results. DDC data is transmitted via a specific pin on the VGA cable and many cable simply omit this pin or just dont attach it to anything!
The result is that the OS just supplies a list of common resolutions and if your monitor fits one, that's fine, but if it doesn't then you have a display problem!

I've just got a DDC enabled cable and the problem vanished!

If you're buying a new monitor, you should probably make sure that the cable you're using is fully wired and using the DDC pins.

Any corrections are most welcome...


More or less as I thought then but only believed it was an issue with Vista which forces DDC while in XP you can override. Ultramon can overcome issue in Vista but it not free software.
 

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