I've just bought this device on amazon.
It is Android 6.0, already rooted. I needed a clean image, not rooted, or at least i try to remove the root, no problem.
So I've found on this forum this image: s905x013.MXQ_PRO+_Mbox_7.1_2G(16)_HS2734A_100M.201 7.10.31.23.49
It's the only working image, all the other images for s905 or mxq (the motherboard code is MXQ_S905X_D4) red led, need to reflash.
Do you have any suggestion? I wrote to the seller for the stock image link but he is ignoring me.
With this firmware I can't boot in twrp, neither update with sd or install magisk (i need some module) and can't remove supersu.
Thanks a lot for your help!
Flavio