Beats me.
See if it still does it with the volume down all the way. Also see if
you hear anything amiss between words in a show. . That may
narrow it down. If its a remote it could be coming from there
also.
BTW is this the set that had afterglow ?? If it is the two things
may be related. That concerns me ( HV)........
73 Zeno
LFOD !