HDMI not recognizing Pi 3 on first boot

Question

On first setup of my Pi 3 Model B I followed instructions to install NOOBS 2.4.5, got a good power cable, swapped the HDMI TV cable from my little Lenovo linux box to the Pi for setup, and ... nothing. But that's where I parted ways with the instructions.

The only keyboard/mouse handy is a Logitech K260 Wireless Keyboard & Mouse (happily shows up on the compatability list ), but they are dongle - not wire - USB. Also, since our hub is all the way on the other side of the room I can't run cable over until kids are asleep, so I'm not networked. I just wanted to test...

But the Samsung TV isn't detecting much of a signal; when I switch "Source", however, it DOES identify this HDMI-CEC connection as "raspberry".

I'll try to make this a less headless boot later with the NIC plugged in, but wondered how many obvious errors I'm making here.

Answer 1

This regularly happens if you dont place the HDMI cable in before booting up. You just have to unplug the pi, insert HDMI, then boot up again.

Answer 2

I have seen this behavior regularly. I suspect it is not so much that the HDMI does not recognize the Pi but that the Pi does not see an HDMI screen. It then falls back to composite.
It is very important that the HDMI screen is on before the Pi. Even then I have seen it fail if you have a screen which does an input scan: VGA, Display port, HDMI etc. The HDMI port is 'valid' for such a short time that the Pi does not 'see' it. I once had to boot four times before it 'caught' the HDMI. If possible set the screen to HDMI mode before booting.
Nowadays I 'edit*' the config.txt file on the PC before the first boot to give it a series of different settings. One of those is to force it to use HDMI.
* I use a windows batch file to change it after writing a new image.