hdmi compatibility

Hi,

I have a macbook pro 2011 and I have bought an LG IPS monitor (27 mp55).

I was used to connect my macbook to a 50" samsung with a Hamma mini display to HDMI converter, but when I use the connector to my LG monitor.

it just writes no connection tries to o to sleep then seems to detect my macbook then again disconnect.

and my built in display restarts stretches , ....

any solutions comes to your mind maybe something I can try?

I thought maybe my theres a physical issue with ports but my cable and monitor are new and I cleaned my converter.

http://www.lg.com/hk_en/support-product/lg-27MP55HQ

https://de.hama.com/portal/articleId*181261/action*2563