new Arch Arm install on RPI2 freezes at Rainbow Image

[ErikL77]

Trying to do a new install of Arch Linux ARM on a Rasperry Pi 2 following the instructions (which has worked without a hitch previously on a Pi 2) but it freezes at the rainbow image.

So far I have tried two different Pi 2:s, I have switched sdcard, I've tried booting from a USB stick with bootcode.bin on the sdcard (and I've edited the fstab and cmdline.txt files), I've switched power source, and I've tried adding the boot_delay to config.txt

No difference.

The same sdcard and installation will boot if I instead us a Pi 3, and I can install raspbian on the sdcard and the Pi 2 will boot without any problem.

Is there anything else that I can try?

[ErikL77]

Well.... The Raspberry Pi I thought was a Pi 2 model B, was in fact a Pi model B+.
I have too many of them and I failed to check /proc/cpuinfo...