I have an ASUS P6T that is about 3 years old. I have an EGA AGP video card, tho I am not sure of the chipset. I use two monitors, VGA and DVI. The computer is used 12-14 hours per day, 7 days a week.
I have some noise in the VGA monitor. Hard to explain, it's diagonal, and it seems to move a bit. I swapped the monitors, still there in monitor #2. Swapped the VGA cable, still there. Swapped the AGP slot (there are two), still there. Took out another vid card from another computer, and put it into the P6T, still there. Took the VGA vid card, and put it into the other computer, noise not there. So, at this point, I seemingly have eliminated the monitor, cable, vid card. That seems to leave the MB as the culprit.
I wanted to see if anyone had any ideas...if there is anything else I can check, or have I covered all my bases? I guess the two things that I find wierd is that both slots exhibit the same problem...if the problem was with the MB, would the problem really show up in both slots? And the other thing is that there is no noise in the DVI signal - only VGA.
Wow, I actually misread that the first time... I didn't catch that you took another card from the other system. Just skipped right over it, for some reason, lol. I just read the part about trying the old card in the other system.
Anyway, I suppose that seals it as the mobo being the problem, although I'll admit that the "noise" not showing up with DVI is confusing. DVI is digital and VGA is analogue, so that makes a little sense, but that should be confined to the GPU, and not affected by the mobo.
Any other time, I would SWEAR that it's the GPU, but I guess not, here.