Seems CTC203 chassis has the same problem. I see that every time you power off and hear a POP from speakers. That is only time speakers made popping noise.
Oh yes, I've been on RCA's service website looking for a bulletin and repair tips, none of them addresses this.
Now I'm really wondering what happened when tv powers off (button or by remote control), the supply voltages doesn't jump around and is not in sync with that pop noise.
But I do can feel the speaker cones move for a fraction of a second if as it had offset voltage applied. The mute circuit works but reacted too slowly to work properly for powering off.
Anything else to deal with this? I checked for glue and not the problem since I cleaned everything off and few parts replaced.
Cheers, Wizard