I wouldn’t suggest to use EBox U-M8 unbrick guide for a non EBox purchase M8 as it can cause of permanent damage to device. We always suggest our users to look for genuine device not a cloned and can recommend some better device if you wish to know as the best selling T8 V3s. Also for your non working M8 device which is not working and with your sole decision you can use the U-M8 unbrick guide of EBox.