My SIM isn't working. What shall I do? Kimchi Mobile Team August 11, 2017 03:59 Updated Follow Please try the following steps: Please Check if the Phone detects the SIM card Please Check if there is a signal with signal bars. Related articles I got my SIM card but data is not working. I need SK telecom (t-world) customer service center contact information How can I check my monthly bills or data usage? How much is the SIM cost? What is the plan of Prepaid SIM card service? Comments 0 comments Please sign in to leave a comment.