Galaxy S8 Plus (S8+) signal bars disappears randomly (no signal issue)

The issue we address in this post is not unique to the Galaxy S8 Plus. In fact, many users reported the same exact situation on older Samsung and non-Samsung mobiles in the past. Basically, what’s happening is that the signal disappears at times, but then re-appears when a user attempts to make a call. If you have such a problem on your Galaxy device, chances are it will disappear by itself over time. For those wanting to do something about it without waiting for your carrier or Samsung to address it, follow our suggestions below.

Problem: Galaxy S8 Plus (S8+) signal bars disappears randomly

Hi there, I have a Samsung Galaxy S8+. It was an upgrade from an S6 & I’m enjoying having good battery life & a fast phone again… I hope it continues. I’m getting an annoying intermittent issue with network signal. I will, on occasions, notice my phone shows no signal bars. However I attempt to ring someone will immediately jump to full/4 bars. This morning I woke up & it has done it again. I asked my wife to call me & it told her I was unavailable (or whatever it says the person you are ringing has no signal/service). I immediately tried calling someone & my jumped to full bars. My wife called me again & she got straight through. While writing this I have watched my bars go from full to empty & I haven’t moved location. I have tried booting on Safe Mode but the issue is still there.

Solution: We’ve seen this issue occur from time to time. We think majority of these cases are caused by firmware coding issues that’s why they also go away after carriers patch them up. To see if your case is fixable at this time, follow our suggestions below.

Restart

Sometimes, this simple procedure can fix bugs that developed after the system has run for a long time. By manually forcing your Note8 to reboot, you’re basically simulating a battery pull, which, in older mobiles with removable battery packs, was an effective way to refresh the system. If you haven’t tried this one yet, here are the steps that you can do:


  1. Press and hold the Power + Volume Down buttons for approximately 10 seconds or until the device power cycles. Allow several seconds for the Maintenance Boot Mode screen to appear.
  2. From the Maintenance Boot Mode screen, select Normal Boot. You can use the volume buttons to cycle through the available options and the lower left button (below the volume buttons) to select. Wait for up to 90 seconds for the reset to complete.

Refresh the system cache

A corrupted system cache usually affects a device by causing it to slow down or suffer from performance issues. At times though, other issues including networking problems may result if this cache becomes outdated or corrupted. To check if a system cache issue is behind the trouble, try clearing the cache with these steps:

  1. Turn off the device.
  2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  3. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
  4. Press the Volume down key several times to highlight ‘wipe cache partition’.
  5. Press Power button to select.
  6. Press the Volume down key until ‘yes’ is highlighted and press the Power button.
  7. When the wipe cache partition is complete, “Reboot system now” is highlighted.
  8. Press the Power key to restart the device.

Reset network settings

This one is a staple for any network troubleshooting. Some network bugs are caused by incorrect network configuration or settings. To see if the cause of the problem lies on your phone’s current network setup, consider wiping its network settings by doing these steps:

  1. Open Settings app.
  2. Tap General management.
  3. Tap Reset.
  4. Tap Reset Network settings.
  5. Tap RESET SETTINGS button to confirm.
  6. Restart your S9 and check for the problem.

Manually change network

Forcing the device to connect to another network sometimes fixes signal issues. Here’s how it’s done:

  1. Open Settings app.
  2. Tap Connections.
  3. Tap Mobile networks.
  4. Tap Network operators.
  5. Force the phone to search for all available networks in the area by tapping on Search networks option.
  6. Wait for a few moments until the device is done scanning.
  7. Select a network (not the one you’re using).
  8. After the device says it is unable to establish a connection or fails to register to the network, select your own network operator.
  9. Wait until the device has registered to the network.
  10. Restart the phone.
  11. Check for the problem.

Check the SIM

If the problem returns after doing the steps above, you can then check if the problem is SIM-related. Try to insert your SIM card to a compatible device (preferably another phone that works on your current network) and see if you encounter the same problem.

Or, you can simply replace the SIM card to see if there’s any difference.

Reset app preferences

Resetting app preferences is oftentimes overlooked in many Android troubleshooting articles but when it comes to an issue like yours, it might help a lot. It’s possible that one or some of your default apps may not be set correctly, causing this glitch to occur. Because there’s no way to know if this guess is true, what you need to do is to simply ensure that all default apps are turned on. Here’s how to do that:

  1. Open Settings app.
  2. Tap Apps.
  3. Tap on More settings at the upper right (three-dot icon).
  4. Select Reset app preferences.
  5. Restart your S8+ and check for the problem.

Reset all settings

This procedure is separate from the previous one as it covers all settings of your Android device and not just the apps. To do this, follow the steps below:

  1. From the Home screen, swipe up on an empty spot to open the Apps tray.
  2. Tap General Management > Reset settings.
  3. Tap Reset settings.
  4. If you have set up a PIN, enter it.
  5. Tap Reset settings. Once complete a confirmation window will appear.

Factory reset

Should nothing worked so far, you should consider reverting all software settings to their defaults. You can do that by wiping the phone thru factory reset. Be sure to back your personal data up before doing it.

  1. Create a backup of your data.
  2. Turn off the device.
  3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
  4. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
  5. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
  6. Press Power button to select.
  7. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
  8. Press Power button to select and start the master reset.
  9. When the master reset is complete, ‘Reboot system now’ is highlighted.
  10. Press the Power key to restart the device.

Contact your network operator

Some network problems are not fixable on a user’s end. If the issue returns after a full reset, let your network operator know about it.