Geeetech's Azteeg X1
There is a deviation of original Azteeg X1 - Geeetech's Azteeg X1. It has reduced PCB with less components. I've had two of this boards, and they both have had the same issue - all driver slots, exept for X was not shorting RESET and SLEEP of A4988 drivers. This resulted in malfunction, but can be fixed by soldering these pins together. Also this version have no ENABLE pin, so the steppers are on all the time.