Video Issues

Setting in /boot/config.txt

hdmi_drive=2

seems to solve issues related to HDMI in some cases.

Can't change Resolution

If you have had to use

hdmi_safe=1

to make your pi display on your display, you will only be able to get 640x480 resolution. To fix this you need to use these settings to allow different resolutions.

hdmi_force_hotplug=1
hdmi_drive=2

and then set

hdmi_group=1
hdmi_mode=16

to force a resolution (those settings are for 1080p 60hz). More options can be found at: http://elinux.org/RPiconfig#Video_mode_options

An example of a forced 4:3 ratio at 1024x768

hdmi_drive=2
hdmi_force_hotplug=1 
hdmi_group=2 
hdmi_mode=16