Monitor flickering, going black

So today I got an LG L196WTQ-WF from a family friend who didn't want her computer or monitor anymore, and I'm using it as a second monitor. But the problem is it's flickering a *** load and also turning black for a couple of seconds and then lighting back up and flickering again, when it goes black the power remains on. I've seen this monitor working like an hour ago on a different computer, so I know it's not the monitor that's broken, and seeing as I'm running two monitors on my graphics card (Radeon 5770) I'm assuming it's not the graphics card, but hey, maybe I'm wrong, I'm no expert.

Any help would be great.

Have you tried using it by itself to verify it works properly? Also, verify that all of your video/monitor connections are firmly connected.

What type of cable are you using (VGA, DVI, HDMI)? Are you using any adapters? Have you tried swapping cables with your known, good monitor?

Sounds like your "new" monitor may be defective. Before declaring it deceased, I suggest you go into its menu and see if you can set it to its original default configuration. You could have a configuration issue in the monitor itself (not likely, but possible).

Do you have another PC/notebook to connect to for troubleshooting?

Here to help, my friend. You are most welcome. Good luck!

Already done that, it's not the backlight.

I've had two Samsung monitors that have done something similar-they would take forever to come on at boot, or out of standby. They would flicker and eventually come on, but once they were on, they stayed on. Eventually, though, they got to the point where they would not "wake up" anymore. Both had bad capacitors, and took probably 5 minutes to fix. And both are still working fine to this day. At this point, you have nothing to lose by opening it up and looking around.

Ok so this morning I used my dad's laptop to see if it's the monitor or what, turns out it is not the monitor, it's working perfectly straight away on my dad's laptop, same cable as well, so it's not the cable, so is it something to do with my graphics card?

Wait, I asked earlier about using the DVI cable on the "new" monitor and you said it still failed. Is that correct?

So, the DVI port on your GPU works, but the VGA port may not be working. That is what you now know, I think. When you connect the new monitor to another system, it worked properly, correct?

Have fun with the laptop. Good luck!