Second monitor disabled after Yosemite 10.10.3 update

Just recently updated my OS and upon restart my monitor decided not to work.

I tested the monitor and others. None now work. I've been using the a thunderbolt to hdmi from eBay. So i instantly thought apple have mad an adjustment for using non apple products. So i unloaded $44 on a thunderbolt to VGA adapter. official adapter. Took it back to the office, plugged it in and nothing. nothing on any screen i try. my macbook air 2014 just flickers like its trying to connect with the external screen. But nothing.

After 4hrs on the phone with apple they insist the next step is to do a clean install. This is a last resort for me and i'm unwilling to be honest to waste all that time and effort re installing etc.

Anybody else have this issue?