Cant Load Fastboot Mode in Obi S454

[AC Question]

i tried all the methods even the adb. Still wen i type adb reboot-bootloader the screen goes blank and then it loads to screen where the fastboot mode with an arrow to its left is shown but no luck it wont load it gets stuck at that time. The power button also doesnt work at that time. I remove the battery to reload it again. Pls help and Thanx in advance