Imagine a non-halting Turing machine that repeats the same calculation forever.
Let us assume that each time it runs its algorithm it increments a loop counter.
Surely such a machine is conceivable in principle?
Now imagine that each time the calculation is performed the Turing machine "wakes up" and finds itself in one of an infinite set of identical conscious moments.
Let us assume that during each moment the Turing machine asks itself the question:
What is the probability that the loop counter currently has some particular value n?
Now the Turing machine's current moment is just one moment in an infinite ensemble of identical moments each with a different loop counter value.
Therefore the probability that the current moment's loop counter value has some particular value n is 1/infinity which is zero.
This reasoning holds true for all loop counter values n.
Thus the probability that the Turing machine finds itself in a moment with any loop counter value must be zero.
But the current moment must have some loop counter value.
It seems that we have a contradiction.
Thus, while a non-halting Turing machine that repeats the same calculation is conceivable in principle, the above argument suggests that a conscious version of such a machine is not.
I think that the problem is with the assumption that a Turing machine can produce conscious awareness by implementing an algorithm.