NY  wrote:
> Any suggestions? Is it some sort of incompatibility between an image that is
> said to be good for RP2 and RP3, and my RP3 B+?

My guess is the image predates the 3B+, and you need to upgrade the
firmware.

If you have another Pi, you can boot the image there and run rpi-update.
Otherwise...

Plug the SD card into your PC and the FAT partition should open.
Then go to here:
https://github.com/raspberrypi/firmware/tree/master/boot
and download the *.elf, *.dat, *.bin files to replace the ones on your SD
card.  Make sure the names are exactly the same (including case).

I don't know if there's a .dtb file on the SD card, but if so replace it
with the bcm2710-rpi-3-b-plus.dtb one from github.

Theo

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