[Q] xt910 black screen after motorola logo topic

hi everyone,

first of all i tried search same problem but there is different i can enter to AP fastboot and recovery press power +up+down

( i have installed on my xt910 cm 11 (4.4.4) using safestrap 3.65 after the offical 5.0.2 rom cm12 come out (http://forum.xda-developers.com/droi...-12-0-t2950906)

i update safestrap to 3.75 then uninstall recovery then reinstall it reboot

delete rom slot and re install now one and then install 5.0.2 rom +gapp reboot (take about 10 min ) and then setup steps goes fine but the Device became annoyingly slow so I tried
to delete rom slot again but this time i select rom slot 2 and wipe then install 5.0.2 rom +gapp then reboot )

motorola logo Appears then no thing black screen actually black light screen (there is no safestrap logo Appear)

i tried ap fastboot and thats what i got

battery low
cannot program
connect usb
data cable

i can go to recovry by press power +up+down
but every time i tried to install (( cm11 4.4.4)) i got install field

thanks and sorry for bad english XD