Note 4 N910a OC6 baseband and imei unknown,bootloop after *#9090#

I have Note 4 N910A at&t 5.0.1 N910AUCU2COC6 now has boot loop problem after pressing *#9090#. with this new 5.0.1 you cannot downgrade so I've already flashed the same version files passed OK but still has this problem. I think phone might have lost baseband now. Any solution to repair this problem, please help. Thanks :crying::crying::crying:
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