192 loss and intermittent connection and then audible clock source

[WestPhillySoulzition]

1/4 of the time. the 192 io is working fine. then all of the sudden in the middle of playback outputs one and two will output an audible clock source. Repetitive pops from output 1/2. Sometimes when I boot up it starts with these sounds, and then other time it boots up and works normally. I have the loop sync set up correctly with the sync IO. but on the front panel of the 192 sync is internal loop sync master, not loop sync master. is that wrong? sorry if I am being vague or unclear. I found one post that said somebody just had to return one of his 2 192s to fix this problem.
any ideas
thanks in advance.