I haven't yet got NetBSD running on my pinebook.
Here's what I did: I wrote Jared's image (I tried different versions)
to SD card and booted from that. I can tell that the kernel gets loaded
and run as I can see the keyboard leds flash and there's a cracking noise
after a certain time when the sound chip gets probed. But I don't get
any console messages or other output on the screen. No Pinebook cone, no
logo, rien, nothing, nada. As even in darkness no glow can be seen from
the display, I think that the backlight remains off during the entire boot
sequence.