I have an iMac, 21.5" (late 2009 model) running OS X Lion, 10.7.1 I have a Mini Display Port to HDMI Adapter I have a 4 metre HDMI to HDMI Cable Plugged the Mini Display Port into my iMac: http://i56.tinypic.com/wlc0p2.jpg Plugged the HDMI into it: http://i51.tinypic.com/2myzps3.jpg Then plugged the other HDMI end into my TV: http://i52.tinypic.com/2uhqngm.jpg Switched the channel onto the HDMI 1 which the Cables plugged into (also tried HDMI 2) went on my iMac to detect displays, but nothing... what am I doing wrong? (first time doing this obviously) All plugged in but when clicking on 'Detect Displays' it just does nothing, nothing happens... and on my LG TV it just says 'No Signal' :-/ My TV picks up the HDMI because when all is plugged in, the HDMI tab on my TV is highlighted (to click onto) but when the HDMI it taken out of the Adapter, the HDMI tab goes grey... so the TV knows the HDMI is plugged into something to use, but the iMac isn't detecting the TV, and the TV just shows 'No Signal' on the Screen.... Im wondering could there be something wrong with the Adapter itself? but then again if something was wrong with it... the TV wouldnt know that it's actually plugged into something for the HDMI 'tab' to become highlighted.... Or could it be OS X Lion? or the HDMI Cable, or the TV? I have no clue, any help would be appreciated.