Do a visual inspection of the sim holder for debris, dust etc, Try cleaning the contacts of both the sim card and holder with applicable contact cleaner or 90% or better isopropyl alcohol (available at any local drug store).
Edit your question to include the model of your unit.
Do a visual inspection of the sim holder for debris, dust etc, Try cleaning the contacts of both the sim card and holder with applicable contact cleaner or 90% or better isopropyl alcohol (available at any local drug store).
Edit your question to include the model of your unit.
prop man さんによる