PcDuino3 Nano image not booting

I downloaded:

http://mirror.igorpecovnik.com/Armbian_5.10_Pcduino3nano_Debian_jessie_4.5.2_desktop.7z

and burned it to an SD card, when I tried booting the board, all I get on the uart console is the

u-boot SPL signon message

+++++++++++++++++++++++++++++++

U-Boot SPL 2016.01-armbian-sun8i  (May 01 2016 - 01:05:19)

DRAM: 1024 MiB

CPU: 912000000Hz, AXI/AHB/APB: 3/2/2

Could not determine boot source

resetting ...

+++++++++++++++++++++++++++++++

This repeats forever...

I had previously used:

http://mirror.igorpecovnik.com/Armbian_5.00_Pcduino3nano_Debian_jessie_4.4.1.zip

and it worked fine on the same board.

I tried recompiling u-boot from source using the Armbian build tools, with the same result.

+++++++++++++++++++++++++++++++

U-Boot SPL 2016.05-rc3-armbian  (May 01 2016 - 10:57:44)

DRAM: 1024 MiB

CPU: 912000000Hz, AXI/AHB/APB: 3/2/2

Could not determine boot source

resetting ...

+++++++++++++++++++++++++++++++

The board is a PcDuino3 Nano Lite which is the same as the non-Lite version except it is missing the NAND and IR receiver.

 any thoughts on what might be wrong??

   ...ken...