Repost from unofficial BBB community:
I’m disappointed with my experience with the BBB. A serious limitation (for me) is that it has a max resolution of 1280x1024. It’s also incompatible with my Sharp Aquos HDTV over HDMI. I even flashed the TV to the latest firmware in hopes that the BBB would recognize the EDID and display correctly. This didn’t work either.
I’ve never had an issue with devices connected to HDMI on this TV. I have a Raspberry Pi hooked up to it right now. Be aware of the limitations of this device and hope that it’s compatible with your TV/monitor.
Here is my attempt to troubleshoot the problem and recommendations.