MDP/Lightning adapter troubles

Hi, I have a mid-2012 MBP Pro retina with Thunderbolt port. I have an external monitor that I haven't used in a while which takes DVI/HDMI. Yesterday I went out and bought a DVI to Minidisplay port (a generic). When I got home, I had to plug it in a few times before it recognized the external monitor. But after a recent reboot, it doesn't seem to recognize at all.

I am thinking this is maybe just because it's a generic cable and if I buy an authentic Apple product it will work, but I'll obviously be annoyed if that's not the case. Any thoughts?

Not all display port adapters are equal. I have found that the adapters that Apple sells work best. I have also purchased adapter cables from monoprice.com which worked well. It does sound like perhaps that adapter you bought might be intermittent. Might be a good idea to try another one.

Seems like it was the adapter. Shelled out for the legit one and it works great.