How do I fix the apple screen loop?

I replaced the logic board, hard drive cable, battery, and the hard drive with an SD card adapter. It restored and in disk mode was able to load music back on no problem. When I exit disk mode and try to use the iPod, it goes to the apple screen, turns off, and goes back to the apple screen, then turns off... over and over.

I don't really know what else I can replace, but figure someone here probably knows more than I do! The SD card reader is the iFlash Solo and the SD card is a 64GB card referenced as working on my model on the iFlash site.