I have recently bought a new GPU (MSI HD7850) and since then have developed very faint wavy lines on my monitor when playing games. These lines are very hard to describe, they are not solid, more like 'ghost' looking and are horizontal across the screen. I guess you could call it a wave effect and easier to see against a dark background.
At first I thought it was the GPU, but I tried with a GTX460 and I had the same problem (tested in GW2). I have tried changing the VGA cables (that's all my monitor can take) and even changed the vga/dvi adapter attached to the gpu.
Am I looking at potentially getting a new monitor here, or am i missing something blatantly obvious?
Oh and there is no other electrical equipment around the PC. Just the monitor and modem.
Could be interference - do you have any speakers near by the monitor/cable? VGA is an analog signal and susceptible to interference - poor quality VGA cables exhibit this condition even more so. Check the cabling in/around the PC - you could try moving them around while the wavy lines are on screen to see if there's any effect.
Also, if you're BIOS has the option, you could try enabling (or disabling if it's already enabled) the 'Spread Spectrum' setting.
Yep newer LCD monitors are designed for digital input first. VGA or analogue input is added as an afterthought.
LCD monitors with vga input only display this short of issue because you are taking a digital signal, converting to analogue (vga) and then taking the vga signal and converting it back to digital to be displayed by the lcd.
With regular CRT's, they are designed for analogue input and that is what they display. As long as the electron gun can synch with the input signal you will get a clear picture every time.
This is why I still use CRT's for troubleshooting older machines, you never know for sure what the output signal will be and since CRT's can synch at all kinds of rates you will almost always get a good picture. I only use my LCD's on new machines that have dvi output etc.