Switches from Wifi to 3G when screen goes dark???

[LBTRS]

Any idea why my Thunderbolt, which had previously been working fine, now switches to 3G when it goes into standby (screen goes dark) from wifi. When I wake it back up it then reestablishes a wifi connection, however, there is a data delay while it reestablishes the wifi connection and I have to wait before I can do anything.

Is there a setting somewhere for it to keep the wifi connection while in standby mode?

Thanks.

 

[paintdrinkingpete]

Any idea why my Thunderbolt, which had previously been working fine, now switches to 3G when it goes into standby (screen goes dark) from wifi. When I wake it back up it then reestablishes a wifi connection, however, there is a data delay while it reestablishes the wifi connection and I have to wait before I can do anything.

Is there a setting somewhere for it to keep the wifi connection while in standby mode?

Thanks.

Sorry to revive an old thread, but I believe I've seen more than 1 person on this forum post about an issue to similar to this.

Just yesterday, I noticed my Thunderbolt was doing the same thing. When I'd wake it up from standby, it would indicate that it was running 4G, then after a few seconds re-connect to wifi. Never noticed this before, and I'm not 100% sure how long this was occurring (but it could not have been for more than a day or two).

I tried the usual stuff, reboots, clearing of caches, etc, nothing seemed to work. I then checked my recently installed apps, the only one of which was "IM+" (a chat client), which I downloaded to do some testing for a pilot program at my work. Long story short, I uninstalled IM+, and the problem seems to have disappeared, although it's only been a few hours, so I can't be fully certain yet.

So...my question is, to anyone else who has noticed this, do you have IM+ installed?

 

[paintdrinkingpete]

Nevermind...that does not appear to be it.

 

[Xxw0lfxX]

Are you by chance running JuiceDefender?

Sent from my ADR6400L using Tapatalk

 

[paintdrinkingpete]

Nope. I bit the bullet and restored a nandoid backup I has from a couple of days ago before I noticed the issue. It seems be working fine now. Not sure what could have caused it though.

 

[nick1020]

Sorry to revive an old thread, but I believe I've seen more than 1 person on this forum post about an issue to similar to this.

Just yesterday, I noticed my Thunderbolt was doing the same thing. When I'd wake it up from standby, it would indicate that it was running 4G, then after a few seconds re-connect to wifi. Never noticed this before, and I'm not 100% sure how long this was occurring (but it could not have been for more than a day or two).

I tried the usual stuff, reboots, clearing of caches, etc, nothing seemed to work. I then checked my recently installed apps, the only one of which was "IM+" (a chat client), which I downloaded to do some testing for a pilot program at my work. Long story short, I uninstalled IM+, and the problem seems to have disappeared, although it's only been a few hours, so I can't be fully certain yet.

So...my question is, to anyone else who has noticed this, do you have IM+ installed?

Its your router. Same thing was happening to me. The wifi would disconnect mostly when the screen was off but sometimes also when the screen was on.
I updated the firmware on my router and it was fixed. It worked for me and a buddy of mine hope it works for you.

 

[NotJustAPhone]

Check your Wi-fi settings to make sure that Wi-fi sleep policy is set to never. Otherwise, when your phone goes to sleep, it will turn off Wi-fi and switch to the cellular network.

Press Menu key/Settings/Wireless & networks/Wi-fi settings

Press Menu key/Advanced/Wi-fi sleep policy

Confirm that Wi-fi sleep policy is set to never

 

[paintdrinkingpete]

Its your router. Same thing was happening to me. The wifi would disconnect mostly when the screen was off but sometimes also when the screen was on.
I updated the firmware on my router and it was fixed. It worked for me and a buddy of mine hope it works for you.

I didn't even think to check that. My router is at the most recent firmware version, but I admit there times when I need to reset it because it starts getting "buggy". All the same though, that wasn't the issue in this case, as this behavior hasn't returned since I restored from backup (my phone is rooted and I had a recent Nandroid back to restore to). All the same though, very good suggestion--I'm sure that could cause very similar behavior if the router is crapping out or failing to hold the connection.

Check your Wi-fi settings to make sure that Wi-fi sleep policy is set to never. Otherwise, when your phone goes to sleep, it will turn off Wi-fi and switch to the cellular network.

Press Menu key/Settings/Wireless & networks/Wi-fi settings

Press Menu key/Advanced/Wi-fi sleep policy

Confirm that Wi-fi sleep policy is set to never

Wow...I though I knew every setting on this phone, and I didn't even that "advanced" menu existed. I'm pretty sure that setting wasn't changed though... it's set correctly now, and I can't imagine anyway that setting would have been changed prior to restoring the backup.


Here's what I do know: yesterday, before I noticed this happening, I was visiting a friend who lives in a "4G fringe" area. My battery was already low and I didn't bring a charger with me, so I switched to CDMA mode (as I have before in the past) to turn off LTE because my battery usually gets eaten alive when I'm there. I got home a few hours later, turned 4G back on and connect to WIFI...and that's when I noticed the problem. I'm not sure if switching the "Preferred Network Type" from 4G to 3G and back again caused it to happen or not, but nothing I did seem to fix it until I restored my phone to the nandroid backup I had from Thursday (and lucky me that I had a recent one!).

If I have time later in the next day or two I may try to reproduce the results to rule that out.