Dual Monitor Problems

[struby]

So I have an LCD monitor and an older flatscreen, and two computers, my older computer, I have set up on the old monitor, and the plan is to put the newer computer on both, but I have a cheap switch that will allow me to switch on the old monitor from old to new computer, with the lcd always having just the new computer on it. Hopefully you are following. My newer computer has a 5770 with 2 dvi ports, on port goes to the new monitor via dvi cable, the other goes to the switch box via vga cable and dvi to vga adapeter, the old computer is hooked to the switch box via vga cable, and the switch box is hooked to the older monitor. At one point I was able to run the new comp on dual monitors no problem, but swapping the cables was a pain, so now I have the switch,

Problem:
but any time I plug the vga cable into the video card on the new computer, neither display shows up, the old monitor is black, and the lcd says no source. I tried restarting and such, whats up? Also, the older display works with the older monitor fine, even with the switch in, but has a flickering issue...

[orbrit]

Here's a few options:

Does your old monitor have VGA and DVI inputs?
If so, plug in the VGA to the old PC and the DVI to the new and just toggle the source.

If it doesn't have DVI/VGA inputs, then maybe you have the primary set to the switched port and not the DVI to new monitor.
Try swapping them (you can always use Catalyst to rearrange them correctly)

If all you're trying to do is get access to the old computer, then another option would be to enable remote desktop and just RDP to it when you need it.

[struby]

I guess I'll try swapping them when I get home today, but when I have both plugged in, the old monitor doesn't show up on the new comp, so I am not sure if the primary thing is the problem or if I follow. by the way the old monitor has only vga.

[struby]

I plugged in only the old monitor to new computer, in the top port of gpu, put it on 600 x 480 (lowest), then kept settings. I then put everything back exactly how it was and, it worked , so thanks guys. My newer comp stays in dual monitor mode despite which one is switched on, but I don't think that will be an issue, only thing perplexing me is this: I then went into Catalyst and went to see if I could take the settings up higher, and it auto adjusted it to 1280 x 1024. Why didn't it just do that before and work, because it is still working, was it maybe trying to run it on the same settings as my lcd, higher than 1280 x 1024, and if so why would my lcd turn off just because the old monitor was not handling the resolution? maybe because they were not matching up, but they don't match up now either, at 1920 x 1080 on the lcd and 1280 x 1024 on the old flat screen monitor, so I don't get it.

and the flickering seems to have gone away, at first when I turned my ac off, and now seemingly always