As a last-ditch effort, I might try WD40s electronics cleaner. DO NOT use regular WD40. You could also try any other electronics cleaner, but I assume WD40s will be more aggressive in breaking down the oil. Make sure to let it dry, then if it seems like the speaker would let moisture into the case; make sure to inspect it for any wetness left over and even check the internals if that is a viable option. I wouldn't try anything crazy unless it's the last thing preventing you from getting a new one. Let me know if you're able to find anything that works. I'd love to hear it.

Hello Jul, This has happened to me twice. In both scenarios, it was an issue with the sim card and not the card reader. I got a free replacement from my carrier, which worked seamlessly after the replacement. I'm not sure how the SIM card actually gets damaged in the first place. I assume it degrades over time or maybe an impact broke something on it. Hope this helps!