Hi, the SD card slot could have a problem internally with it so you may need to get that fixed here is GoPros contact link: https://gopro.com/help/ContactUs. The battery if you can remove it may be old and dying. Rechargeable batteries only can live so long so you may need to order a replacement one for it. I had this problem with my Hero 5 Black, I ordered a new battery and now its fine. Hope this helps, have a good day.