I’m currently having an issue with a SIM card that can’t be read by an LTE chip. It was deployed in a product outdoors where the temperature dropped to around -20C and the connection suddenly dropped and never reconnected (despite firmware attempting to do so). When troubleshooting at room temperature, the connection was only successful after removing and replacing the SIM card, which points to SIM card holder pins not making contact with the SIM card. A visual observation under a microscope showed no obvious signs of oxidation on the SIM card.
The system was power cycled prior to replacing the SIM card and the problem still existed therefore I ruled out the SIM card state as a possible cause of failure.
Is this a documented phenomenon? The temperature specs for the SIM card and holder are below -20C, but it seems plausible that the cold temperature caused the metal SIM card holder pins to contract enough to lose contact with the SIM card and oxidize, somehow never allowing the electrical connection to be reestablished. Any insight is much appreciated.