For those that own a Samsung Galaxy S7, you may be wanting to know how to fix a No Service error signal problems on your Galaxy S7. This issue is similar to not being able to make proper calls without signal errors on your Galaxy S7. It’s recommended to read how to restore IMEI number and fix no signal error  before continuing with this article, as the linked article generally fixes the No Service error and signal problems on a Samsung Galaxy S7 smartphone.
Issues Causing Samsung Galaxy S7 Signal Error
The main reason that the Galaxy S7 signal problem occurs is because the radio signal is turned off on the smartphone. This signal sometimes turns off automatically when there is an issues with the WiFi or with the GPS.
How To Fix Signal Problems On Samsung S7
- Go to the dial pad.
- Type in *#*#4636#*#* with the dialer. There’s no need to press the send button, though, as the device will automatically enter into Service Mode.
- Select Device Information or Phone Information.
- Select Run Ping Test.
- Click on the Turn Radio Off button.
- Select Reboot.
Fix IMEI Number
When there is a No Service error on the Galaxy S7 and it’s not related to the radio signal, most of the time it occurs because of a nulled or unknown IMEI number. The following article will teach Samsung Galaxy S7 owners how to check if the IMEI number is nulled or corrupted: Restore Galaxy Null IMEI # and Fix Not Registered on Network. 
Change SIM Card
The SIM card can also be an issue causing the signal problem and by checking to see if the SIM card is inserted correctly or replacing the SIM card with a new one, this is another solution that could potentially fix the signal issue on the Samsung Galaxy S7. You can eject the SIM card by inserting the specialized ejection pin into the card tray along the top edge of the phone.