2020 TU8500 50" Intermittent Sound Loss

[david_h]

I have an Amazon Fire Stick 4K which I previously used without problems on my previous TV, a Panasonic. I connect the TV to my sound system via an optical cable. The sound drops out occasionally, ranging from extremely briefly to a second or so. There is no disruption to the picture but the loss of sound is really frustrating. I can sometimes go for almost a whole evening without a drop-out and then I get several. A Google search shows that this has not been uncommon for Samsung TVs in the past, although I can't find any hits relating to this (2020) model. I've tried all of the suggested fixes that I've found so far. These include:

• Disabling the Smart Hub
• Disabling Anynet+
• Switching the Amazon Fire Stick from HDMI 2 (which was eARC) to HDMI 1
• Power off and on again
• Factory reset (with all the effort of re-defining all of my settings)
• On the Fire Stick, changing the sound setting from "Best Available" to "Always Dolby Digital" and, when that made no difference, to "Stereo".

None of the above made a permanent difference.
I also ran the sound diagnostics from the Support menu- these ran clean.
I've only had this TV for about five weeks but I've already disposed of the packaging. It was a Which? Best Buy and seems to have lots of very positive reviews, but if I'd checked with Google for sound problems I certainly wouldn't have bought it. As I write this, I've been waiting for an hour for a Samsung Expert to contact me, despite the chat window saying that one should be able to support me via Chat in 15 minutes.
I then had a chat lasting over 90 minutes where Chris from Samsung Chat support, where he walked me through much of the above. He eventually said that he would book an engineer's visit, and I quote:
"Thank you for patiently waiting. Already schedule the date on Monday 16th of November 12 in the afternoon, they will be calling you before going to your place to check the availability. This your service order number xxxxxxxxxxx, that will serve as reference."
I received an email saying that Martin Dawes (the support partner) would be in touch with me. However, Chris' message stated that a date had been scheduled. At 14:00 I rang Martin Dawes who said that Chris shouldn't have given me a date or time and told me that the next available slot was on 24th November.
I'll repeat that I didn't have problems with my previous TV and I would expect this one to work just as well with the Amazon device. My sound systems shows the PCM rate except that it shows "Unlocked", indicating no input, when the sound drops out.

Any suggestions are welcome, and thank you for reading this far.

[DUMITRU79]

Maybe the Firestick received an update and it messed all that up?
Do you have another Firestick you could test ?

[david_h]

I'll recheck the software level of the Fire Stick. It only seems reasonable for me to try it in another device and I'll see if I can reproduce the problem using my PC's external monitor. For the time being, I'll accept the Fire Stick as the cause as the problem only seems to occur when I'm using that.

[Travisc]

I have the RU8500 and have the same problem. Only have the issue with the 4k max. I've tried two and same result with both. My previous fire TV 4k and 4k stick did not have this issue with this TV 

[david_h · Accepted solution]

Hello, Travisc-

My apologies to this thread for not updating it with my further findings. This issue was caused by a mismatch between the output from the TV and the DAC chip in my CD player, an Audiolab 8300CD (this does the Digital to audio conversion as an input to the amplifier). The DAC in question is the ESS Sabre DAC

The solution for this CD player was as follows:

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"There have been changes the way DPLL is used on the 8300CD.

The Audiolab 8300CD does have the built in Jitter rejection DPLL function to compensate for sources with high jitter for example an optical output from a TV, jitter is noise on the signal.

Please select for example Optical1 input on your 8300CD

Default setting: Low

Hold down the Prog button on your remote for 2 seconds to enter the DPLL Jitter Rejection option, now use Next track or previous track buttons to select “High” then press play/pause button to save the setting the display will resume after three seconds."

This is different to the instructions for Jitter Rejection in the manual that was supplied with my CD player, which is why it took me a while to find the solution.

Different devices with the same (ESS Sabre) DAC will almost definitely have different instructions, I'm afraid.

Good luck, and I hope that this helps a little.

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