ROM tested on 3 bbgto.
Try erase flash
And them flash .
No flash twrp with start with this ROM.
Flash 5.0.2 your device reboot in start to recovery stock . and automatic format nand. Only after you boot to desctop you can flash twrp . 2.7.0 can't reparation band .
Thanks for your help, I flash twrp in recovery partition success, I can enter twrp meun now, I try to restore your twrp backup, I can see desktop,I can use it, but when the tablet sleep, the screen go back to black screen with the word "android", after about 10 second, go back to desktop. So my tablet can not sleep now.