I was having a similar issue which I finally figured out last night. For me the TV & Angstrom were both indicating that there was no connection what so ever. This didn’t make sense, as I had made sure to purchase one of the known good HDMI cables from the WIKI page (http://elinux.org/Beagleboard:BeagleBone_Black_Accessories#Working_HDMI_Cables).
As it turns, I get video out when I removed the BBB from it’s case. Apparently the Adafruit Clear Top Case (http://www.adafruit.com/products/1555) & the Monoprice cable (http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10253&cs_id=1025301&p_id=7557&seq=1&format=2) from the WIKI don’t play nicely together. The cable seems like it is in all the way but is just tiny bit shy.
Now I just have to decide which component I am replacing.
Scott