|"Is this with a monitor connected to a desktop computer, or a monitor connected to the video port on a laptop or netbook computer ? "|
The latter are likely to have a weaker video signal.
Viewsonic VA1916w (home support page)
"1440x900 optimum resolution"
Analog RGB analog (75 ohms, 0.7 Vp-p) "
"WSXGA" - Wide Screen XGA
Click on Downloads
- User Guide
See page 9, 11
If you don't have the CD that came with the monitor....
- Drivers - 4 possible downloads - choose Vista
32 bit or 64 bit, whatever your Windows 7 operating system is.
"monitor drivers (there were only for win vista)..."
Lots of things don't have Windows 7 drivers. Vista drivers usually work fine in Windows 7.
"One day i bought the longer cable.I use it and everything ok at native res.BUT, next time i boot my system and sudenly---->1280x1204....oups...i reboot...the same....i use the short cable,the old one and....everything ok again....native res again.
Yesterday i did the same...long cable-->ok res-->reboot-->low res--->short cable--->reboot-->ok res."
How long is the total length of the cable ?
Assuming the video cable has no problem with it's connection, your longer cable is probably sucking up too much of the video signal. It takes more "oomph" to load a higher resolution..If the total length between the monitor and the video port is more than , say, 12 feet, it should be a thicker, heavy duty cable, much thicker than a normal video cable, to reduce the amount of the video signal that is lost in the cable
E.g. Heavy duty...
VGA (family - analog) extension cables
If you can't do anything about the cable, or in any case, the cheapest way to boost your video signal is to buy a 1 input to two or more output video splitter box and connect that between your monitor and the video port, as close as you can to the video port. The box type all have a built in amplifier. The cheapest are for a VGA connection. You may also need an additional video extension cable, or a gender adapter to change a cable end connector from male to female or visa versa. .
Note that most of them, if not all of them, are rated for the max resolution they can support.
There also devices that boost HDMI cable video signals.
" downloaded nvidia drivers...nothing...."
Installing newer or older video drivers than you were using before, or re-loading the same video drivers, for your video adapter, can change the default setting the monitor is set to.