So, this story does not end well.
I received the "part" last week, a bag of five optocouplers. A bad sign was that there was no number on any of the optocouplers in the bag.
So I spent three hours disassembling this POS, and I can tell you it is just that. Absolute junk not designed to be repaired.
Anyhow I get the board out, and the pin out of the Chinese optocouplers is not remotely similar, and can not be installed.
The broken removed part is on the left, and one from the bag of five on the left. They are not remotely similar and in no way can be fitted on the board as you can see in the photograph.
So that unit is a bin job, and off to the recycling center.
So now you know why their are only vintage repair guys left. That includes myself now. That is the last time I get involved in modern junk.
Avoid sound bars, and if you must buy the absolute cheapest.
Now you know why I have so much vintage gear, and keep it in use wherever feasible, and keep modern gear to the minimum.
Current design practices and the whole home electronics industry needs an absolute shake up.
There should not be 2,500 optocouplers available in the parts suppliers. I can't see why we need more that six and could probably do with less.