Phone says SIM not detected

Symptoms

• Phone shows 'No SIM' or 'SIM not detected'
• No signal bars at all
• Message appeared suddenly with no phone changes
• Error clears briefly after restart then returns

Likely causes

• CommonSIM card not seated properly in the trayA tray that isn't fully clicked in breaks the electrical contact.
• CommonDirty or corroded SIM contactsDust or oxidation on the gold contacts can block the connection.
• PossibleSIM card physically damaged or wornScratches or cracks on an old SIM can cause intermittent detection.
• PossibleCarrier-side account or network issueA suspended line or network outage can look identical to a SIM problem.
• Less commonPhone's SIM reader hardware failureAfter a drop or liquid exposure, the SIM tray reader itself can fail.

What to do

1. Power off the phone, eject the SIM tray with the ejector tool, and reseat the SIM card firmly.
2. Wipe the SIM's gold contacts gently with a dry, soft cloth or eraser to remove grime.
3. Try the SIM in another compatible phone to see if it's detected there.
4. Try a known-working SIM in your phone to see if the problem follows the SIM or the phone.
5. Restart the phone after reseating the SIM.
6. Update the phone's software, since carrier settings updates sometimes resolve detection bugs.
7. Contact your carrier to confirm the line is active and not suspended for billing or other reasons.

Tools and parts

• SIM ejector tool or paperclip
• Soft dry cloth

When to call a pro

If the SIM works fine in another phone but your phone won't detect any SIM, the phone's SIM tray or reader likely needs professional repair.

Safety