rx 480 rig problem

hi guys i need your help regarding my rx480 rig
im using claymore 7.1, msi ref card rx480 using 31mh rom of boysie.
the problem
is after 20-30 minutes my rig restart when i try to monitor it for 20 monutes
ive seen one pf my gpu hash 0.00mhs. ive already reinstall os win10 and gpu driver 16.9.1
but still it close always or restart please help me.