In boot loop 5 or 6 times then goes black
OK i have a Samsung Galaxy S5 which has never had a screen replaced or ever been damaged.
When it was brought in it was just a blank screen the phone is on as i can hear when it rings gets messages ETC it also vibrates too.
I took the battery off so i could restart it it does start up & comes up with the Samsung Galaxy S5 start up graphic then loops sometimes 5 times sometimes 6 then the screen goes black.
When the screen goes black the buttons along the bottom light up fine when activated.
I can't tell if the backlight is on when its black i don't think it is.
Any help or suggestions would be greatly appreciated.
Thanks in advance.