Need help - Onkyo TX-NR801

I have a Onkyo TX-NR801 receiver hooked to polk speakers (RTi6 - Front, CSi5- Center, RTi4 - Rear, Velodyne DSP 10 sub woofer)


I configured the receiver using the manual and it sounds great with volume level up to 65. But, when I keep it at 67, the receiver automatically shuts off. I thought the receiver is powerful enough to handle volumes upto 80. Didn't get much help from onkyo support.


Any help would be greatly appreciated.


Thanks,


Braum