my comp : iMac 21,5 Late 2013
my projection device : Viewsonic PJD5155
problem : mac does not detect external display when i plug cable with converter hub, screen turns into black and detect screen ( detect but no signal, just icon on toolbar ) than turn into black again and no icon on toolbar. it goes like that.
I plugged my HDMI cable to my iMac via converter hub and I use it for a 2 weeks without any problem. Than I bought a new HDMI cable and now iMac does not detect external display. I thought that it is because my new cable and plug the previous one to my mac again but problem does not solved.
Projection device has problem?
I tried to use my projection device via my laptop ( windows ) and projection works perfectly. so i do not think that my projection device has problem.
Converter Hub/Adaptor could have a problem?
I tried to plug a TV to my mac with same HDMI cable and Adapter. Mac detect it perfectly and shows my mac screen as mirror ( thats what i want ) . It seems like my adaptor does not have any problem.
Extra Infos about problem :
I tried SMC and PRAM reset. I Update OSX. and internet recovery ( still same problem )
apple > about this mac > display > display settings hold the "alt" button and click "detect the screens"
