iPhone Signal Suddenly Disappears and Only Shows "No Service", Here's the Cause

The signal or cellular network on an iPhone can suddenly disappear, with the bar only showing the status “no service”. This message essentially indicates that the iPhone is not connected to the cellular network. If this status appears, users will face difficulties because the iPhone cannot access the internet or make calls via the cellular network. So, why does the iPhone signal disappear and show “no service”? As a result, the iPhone signal bar will be empty and may display “no service”. If encountering this issue, one solution is to move to a location covered by the cellular operator’s signal. Additionally, try turning the aeroplane mode on and off on the iPhone. Or, remove the SIM card and reinsert it. This method helps reload the cellular network connection to the iPhone. Secondly, the cause of no service on the iPhone can also be due to bugs or disruptions in the system. If there is a bug, Apple usually provides fixes through operating system updates or cellular operator settings updates. When the iPhone shows no service, try updating the operating system or cellular operator settings. To update the operating system, check via the settings menu, then open the “General” option and click “Software Update”. If an update is available, click “Download and Install”. Then, to update the cellular operator settings, open the “General” option and look for the update option next to the carrier column. If that option is available, proceed with the update. When the Baseband IC is damaged, the iPhone automatically cannot receive cellular network signals even with a SIM card installed. The iPhone will only display “no service” on the signal bar. If there is hardware damage preventing reception of cellular network signals, immediately take the iPhone to a trusted service centre for further repair. Finally, the cause of no service on the iPhone can be due to the IMEI (International Mobile Equipment Identity) not being registered in the government database. When unregistered, access to the cellular network on the iPhone will be blocked. If blocked, the iPhone will only display “no service” on the signal bar. It should be noted that since 2020, the government has been aggressively curbing the circulation of various foreign phones, including iPhones, distributed illegally (Black Market/BM). Control of BM iPhone circulation is carried out through IMEI registration to the Ministry of Industry or the Directorate General of Customs and Excise. When an iPhone’s IMEI is registered, the device can be used to access the cellular network. Conversely, if the IMEI is not registered, the iPhone is indicated as a BM phone, and the consequence is that its cellular network access will be blocked. This BM phone control policy is what can cause the iPhone to show no service.