lbbedendo/raspberrypi_hdmi_signal.txt

## raspberrypi_hdmi_signal.txt
Reference: https://www.raspberrypi.org/forums/viewtopic.php?t=34061

The Pi outputs a relatively weak HDMI signal. Some devices may not immediately notice the Pi's HDMI or may not do the negotiation.
Setting the hdmi_force_hotplug=1 makes sure the Pi believes the monitor/TV is really there.
You might also need to set config_hdmi_boost=4 or even higher (up to 9) if your display needs a stronger signal.
If the display is a computer monitor, use hdmi_group=1 and if it is an older TV, try hdmi_group=2.
Do not set hdmi_safe=1 as that overrides many of the previous options.
Using a shorter or better quality HDMI cable might help.
Make sure your Pi's power supply delivers 1A and not 500mA.
If you see a problem with the red colour - either absent, or interference - then try a boost. However it might simply be that the display requires a stronger signal than the Pi can give.
	Reference: https://www.raspberrypi.org/forums/viewtopic.php?t=34061

	The Pi outputs a relatively weak HDMI signal. Some devices may not immediately notice the Pi's HDMI or may not do the negotiation.
	Setting the hdmi_force_hotplug=1 makes sure the Pi believes the monitor/TV is really there.
	You might also need to set config_hdmi_boost=4 or even higher (up to 9) if your display needs a stronger signal.
	If the display is a computer monitor, use hdmi_group=1 and if it is an older TV, try hdmi_group=2.
	Do not set hdmi_safe=1 as that overrides many of the previous options.
	Using a shorter or better quality HDMI cable might help.
	Make sure your Pi's power supply delivers 1A and not 500mA.
	If you see a problem with the red colour - either absent, or interference - then try a boost. However it might simply be that the display requires a stronger signal than the Pi can give.