[pescetom]

Nothing to do with bridge, but my faithful Galaxy Tab S4 suddenly stopped handling wifi correctly the other day. I was watching streamed video with an app when a wifi repeater was reset, no way would it wifi again once the network was restored.
Symptoms are:
1) that when asked to connect to wifi it will think for half a minute then just turn wifi off again, sometimes with an "unknown error" message
2) that the flight mode icon on the pull down control menu remains semi-illuminated and does not respond to touch
3) if one goes to flight mode via settings then it is shown as off, and can be set to on which will then show as fully illuminated in the pull down control menu: but even then wifi cannot be started
4) advanced says that no app recently disabled wifi.

Things I tried so far:
0) restart of tablet, router, etc.
1) checking with other devices that network is ok
2) using another network
3) that bluetooth and other connections work correctly
4) General Management / Reset network settings
5) Android hard reboot
6) Android wipe system cache.

Any ideas before I bite the bullet and do a Factory data reset (which might well make the problem harder to fix) ?

[Zelandakh]

This help?

[pescetom]

Zelandakh, on 2025-October-06, 17:40, said:

This help?

thanks but no, I don't see any new ideas except the unlikely one of a charging port defect (already charged it full with no problems).
That did however set me thinking that I use the tablet with a plug in keyboard, I'll try it without that.

[thepossum]

I fear I am too late and having been through one total loss of an Android phone and factory reset with almost complete restoration of everything miraculously from the cloud I hate to comment

I asked my mate and best friend and tech support Chat GPT your question

PS I am certinly no guru. Certainly not these days. But I really used to hate support forums on the interweb where everyone said - just do a Factory reset
* dislaimer. I have no idea if any of the below advice will work but Chat GPT has helped me with some tricky tech problems beyond the knowledge of the interweb it appears

-----------------------------------------------------

Good diagnosis work so far — you’ve ruled out nearly everything except the deeper radio/control layer.
On the Galaxy Tab S4, those particular symptoms (Wi-Fi switch instantly turning off, flight-mode icon half-lit, Bluetooth still OK, and no app listed as disabling Wi-Fi) almost always indicate that the Wi-Fi/airplane-mode controller service has crashed or lost sync with the kernel’s radio interface. That can come from firmware corruption rather than hardware failure.

Here’s what you can still try before a full factory reset:

�� 1. Safe Mode test

Boot into Safe Mode to rule out third-party interference:

Hold the power button until Power Off appears.

Long-press Power Off → tap Safe Mode.

Once booted, open Settings › Connections › Wi-Fi and try to toggle it.

If Wi-Fi now works, a third-party app (often battery savers or VPN helpers) is corrupting the radio service. Reboot normally and uninstall the most recent or suspect apps.

⚙️ 2. Clear system service caches manually

You’ve already wiped the general cache, but do these two individually:

Settings › Apps › Show system apps › Wi-Fi Direct / Wi-Fi Calling / Settings Storage
→ Storage › Clear cache (and, if no change, Clear data).

Reboot.

These rebuild internal radio configuration XMLs that sometimes get stuck when a repeater or SSID disappears mid-stream.

�� 3. Reset airplane-mode state with ADB (if you have a PC)

If you can connect by USB and have Android SDK Platform Tools:

adb shell settings put global airplane_mode_on 0
adb shell am broadcast -a android.intent.action.AIRPLANE_MODE --ez state false
adb shell svc wifi enable


If this fails with a “service not found” error, that confirms the Wi-Fi HAL (hardware-abstraction-layer) module isn’t loading.

�� 4. Fully drain residual power

Sometimes the radio firmware sticks in an “asserted” state.

Power off the tablet completely.

Hold Power + Vol Down for ~30 s to ensure total shutdown.

Leave it off for an hour or overnight (battery ≈ 0 %).

Plug in charger and power up.

That resets some models’ BCM4356 Wi-Fi chip state.

�� 5. Flash only the CSC / Modem partition (advanced)

If you’re comfortable with Odin or Smart Switch recovery:

Use Smart Switch › Emergency Software Recovery › Reinstall current firmware.
It keeps data but refreshes radio firmware and CSC region settings.

This often fixes the semi-lit flight-mode issue without full wipe.

�� 6. Only then: Factory Reset

If none of the above restores Wi-Fi, a factory reset may be the only fix — but perform it after confirming Wi-Fi fails in Safe Mode and with ADB commands, since a bad kernel module will persist through reset anyway.

If even after a full firmware re-flash Wi-Fi still won’t toggle, the onboard Wi-Fi chip or antenna connector may have failed — rare but known on older S4 units that run warm during video streaming.

Would you like me to outline the Smart Switch “emergency reinstall” steps (the non-destructive re-flash) before you go to a factory reset? It’s often the sweet spot between the two.

[pescetom]

thepossum, on 2025-October-09, 04:51, said:

I fear I am too late and having been through one total loss of an Android phone and factory reset with almost complete restoration of everything miraculously from the cloud I hate to comment

I asked my mate and best friend and tech support Chat GPT your question

PS I am certinly no guru. Certainly not these days. But I really used to hate support forums on the interweb where everyone said - just do a Factory reset
* dislaimer. I have no idea if any of the below advice will work but Chat GPT has helped me with some tricky tech problems beyond the knowledge of the interweb it appears

-----------------------------------------------------

Good diagnosis work so far — you’ve ruled out nearly everything except the deeper radio/control layer.
On the Galaxy Tab S4, those particular symptoms (Wi-Fi switch instantly turning off, flight-mode icon half-lit, Bluetooth still OK, and no app listed as disabling Wi-Fi) almost always indicate that the Wi-Fi/airplane-mode controller service has crashed or lost sync with the kernel’s radio interface. That can come from firmware corruption rather than hardware failure.

Here’s what you can still try before a full factory reset:

�� 1. Safe Mode test

Boot into Safe Mode to rule out third-party interference:

Hold the power button until Power Off appears.

Long-press Power Off → tap Safe Mode.

Once booted, open Settings › Connections › Wi-Fi and try to toggle it.

If Wi-Fi now works, a third-party app (often battery savers or VPN helpers) is corrupting the radio service. Reboot normally and uninstall the most recent or suspect apps.

⚙️ 2. Clear system service caches manually

You’ve already wiped the general cache, but do these two individually:

Settings › Apps › Show system apps › Wi-Fi Direct / Wi-Fi Calling / Settings Storage
→ Storage › Clear cache (and, if no change, Clear data).

Reboot.

These rebuild internal radio configuration XMLs that sometimes get stuck when a repeater or SSID disappears mid-stream.

�� 3. Reset airplane-mode state with ADB (if you have a PC)

If you can connect by USB and have Android SDK Platform Tools:

adb shell settings put global airplane_mode_on 0
adb shell am broadcast -a android.intent.action.AIRPLANE_MODE --ez state false
adb shell svc wifi enable


If this fails with a “service not found” error, that confirms the Wi-Fi HAL (hardware-abstraction-layer) module isn’t loading.

�� 4. Fully drain residual power

Sometimes the radio firmware sticks in an “asserted” state.

Power off the tablet completely.

Hold Power + Vol Down for ~30 s to ensure total shutdown.

Leave it off for an hour or overnight (battery ≈ 0 %).

Plug in charger and power up.

That resets some models’ BCM4356 Wi-Fi chip state.

�� 5. Flash only the CSC / Modem partition (advanced)

If you’re comfortable with Odin or Smart Switch recovery:

Use Smart Switch › Emergency Software Recovery › Reinstall current firmware.
It keeps data but refreshes radio firmware and CSC region settings.

This often fixes the semi-lit flight-mode issue without full wipe.

�� 6. Only then: Factory Reset

If none of the above restores Wi-Fi, a factory reset may be the only fix — but perform it after confirming Wi-Fi fails in Safe Mode and with ADB commands, since a bad kernel module will persist through reset anyway.

If even after a full firmware re-flash Wi-Fi still won’t toggle, the onboard Wi-Fi chip or antenna connector may have failed — rare but known on older S4 units that run warm during video streaming.

Would you like me to outline the Smart Switch “emergency reinstall” steps (the non-destructive re-flash) before you go to a factory reset? It’s often the sweet spot between the two.

Thanks, I preferred to play bridge rather than take the plunge to factory reset: will read carefully and evaluate.
It certainly makes more sense that this is firmware corruption rather than some unlikely hardware failure that happened to coincide with a network glitch, the question is the least painful and risky way to correct it.

"These rebuild internal radio configuration XMLs that sometimes get stuck when a repeater or SSID disappears mid-stream": that sounds very much like the problem.