A few days ago I bought a TCL 55S425 Roku tv, upgrading from my TCL 49S405 Roku tv. Ever since setting up my new 55 inch, the speaker it is connected to randomly will emit a loud popping/crack noise. It happens for a brief second, and it will repeat probably every 20-40 minutes. I have my 55inch connected to a Woburn speaker using a aux cord using the headphone output. My 49inch TCL was setup the exact same way to my speaker, and never once did I experience the pop/cracking noise that I do now. I made sure that my 55inch is updated fully, so that doesn't seem to be the issue. I also turned the audio to stereo instead of auto-detect. This is very frustating, my older tv had no issues with the setup.
Fixed! Have had my tv 1 year and just today it started crackling. I turned leveling "off", as suggested and the crackling is gone! It must have always been on this setting so it is odd that the crackling just started but I'm relieved for the fix!
I am having a similar issue on my 55S425 which I purchased yesterday. Whenever coming out of a fast forward situation while watching, DVR, Netflix, etc. There is a brief "electric" popping sound. I am using the internal speakers and I have done a full factory reset.
So mine unfortunately was my receiver. Think something was shorting it’s because it would go into safe mode. Once I replaced it, all was good. Now on my sling tv though there’s a slight delay and no settings fix it