Rainbow screen must die!

Can I PLEASE get some help?

My firestick died 2 weeks ago. Would not boot up.. just a black screen. Called Amazon and it was under warranty so they sent me out a replacement. When I plugged it in all it showed is this rainbow screen with blocks of color all across it and in the bottom left corner “=>normal boot”. I’m not able to select this or arrow over to it in any way. Called Amazon back a 3rd time. They say it must be defective and sent out another replacement which is doing the exact same thing!

I’ve tried switching to different inputs-didn’t work.
I’ve tried plugging my Roku into that same input and it works just fine.
I’ve tried different hdmi cables-didn’t work.
I’ve tried holding the right side of circle and back button for 10 seconds. Nothing.
I’ve tried holding the ok button and the play button for 10 seconds. Nothing.

Does anyone know what’s wrong? I miss my Kodi!