why does my tab a sm t550 9.7" keep restarting even after i have flashed it twice

[AC Question]

i have recently bought a tab A 9.7" but now im having issues with it i have taken it to the shop to check out they flashed it twice but the restating of my tab A is still persistant, please can any one help me and show me step by step methods of what to do i have also factory restarted it and pressed the power , volume and home button but nothing works
PLEASE HELP ME

 

[B. Diddy]

Welcome to Android Central! Remove any SD card that might be inserted and try rebooting again. If that doesn't help, then I would suspect some defect in the motherboard. Did you buy this tablet new or used? If it's still under warranty, contact Samsung.