I got Rock 5B but no output

Today i received my Rock 5b 4gb and i start it with SD card installed ubunto.
But it stayed nothing with solid green led.
And I pushed recovery and power button but nothing happened. (Anyway what these buttons do?)
What should I do?

I tried another SD card with debian.
But it’s nothting too.

You can check out this tutorial. https://wiki.radxa.com/Rock5/install/microSD

Yes, I’ve followed the page.
I think it is about power.
My USB adaptors are 1~2.1 amp with 5V.
Is it not enough for Rock 5B?
Some adaptor show me some booting lines but it goes to black again.

you need a pd power supply for the rock 5b

Oh, Thank you.

It means that I can’t use my iphone USB adaptor for Rock 5B, right?

no but a newer macbook adaptor should work

Thank you for the info.