Develop Bugs

[Q] G2 - No SIM, No Wifi Connection?

I have a G2 that is unlocked, rooted, and uses Cyanogenmod. I deactivated Tmobile service, and since the WiFi won't connect. It says obtaining IP and then won't connect.
I have done all the needed router tweaks. That I suspect is not the issue. I believe that the Tmobile allowed me on my Wifi, but had to register with the WAP network each and every time it used it. This would make sense, as when I tried to use programs like GrooveIP and Talkatone, it had extremely poor connection, as if it were making extra IP hops.
What I'd like to know after searching for many hours is - can I use the WiFi on it with no SIM or active service? I had a Nexus One that would do just that, but this G2... no dice.
HELP!

So no one has any ideas? Anything I can check? At all? I'd really like to use the wifi on this device at least...

Sounds weird. Try resetting your router. I noticed sometimes it says obtaining IP adress but doesn't connect, and when I restart the router it works. Just took the SIM out of my phone and it works. T-Mobile has nothing to do with the WiFi...especially since I'm using an AT&T sim in mine.

Have u tried changing the wifi channel?
Sent from my HTC Vision using xda premium

I think the problem in this one is your router, not your phone, but to make sure, can you try your device on another wifi network? If it connects you should take a look at your router settings. Maybe it won't let a device connect if it's on a lower speed (as phones do not have the highest wifi speeds...)
If you're able, try the phone on another wifi network and let us know if this works..

Mine occasionally hangs at "Obtaining IP from.." also no matter what rom I used and I have active tmo service. I normally either reboot or toggle airplane mode on and off and that will usually solve the problem anytime it isn't router related.
Sent from my HTC Desire Z using XDA

WiFi glitch with WiFi extender

Hi, I am using Calkulin's 2 v1.6 ROM, with FE22 modem.
I noticed that WiFi on the phone keeps crashing, when I am trying to access internet via WiFi extender. When I am connecting via router no problems at all.
My friends also have E4GT, with stock EL29 firmware and modem, and they don't have any issues connecting over WiFi extender.
I tried other devices (iPhone 4S, iPod, laptops, netbook, etc.) those have no issues over WiFi extender either.
I tried just flashing the modem to EL29, FF02, FF18 and the results are the same as with FE22 (WiFi crashes and restarts on the phone).
Any remedy or anyone else having similar issues?

WiFi extender?? Are you talking about a repeater or an app?
I saw an app on the market claiming to 'extend' the wifi range of your phone. Obviously a bunch of bs. Hopefully that's not what you're talking about.

lindros_nyr said:
Hi, I am using Calkulin's 2 v1.6 ROM, with FE22 modem.
I noticed that WiFi on the phone keeps crashing, when I am trying to access internet via WiFi extender. When I am connecting via router no problems at all.
My friends also have E4GT, with stock EL29 firmware and modem, and they don't have any issues connecting over WiFi extender.
I tried other devices (iPhone 4S, iPod, laptops, netbook, etc.) those have no issues over WiFi extender either.
I tried just flashing the modem to EL29, FF02, FF18 and the results are the same as with FE22 (WiFi crashes and restarts on the phone).
Any remedy or anyone else having similar issues?
Click to expand...
Click to collapse
I have been on any number of roms/modems... In addition to my main one I have 3 routers flashed over to dd-wrt and used as repeaters throughout the house (yes, my wifi signal strength is EXCELLENT, EVERYWHERE!). I have never had any wifi connectivity problems nor have i seen this issue elsewhere on the forum before. Is it possible that a simple mistake is causing it, like a mistyped password saved as default?

lindros_nyr said:
Hi, I am using Calkulin's 2 v1.6 ROM, with FE22 modem.
I noticed that WiFi on the phone keeps crashing, when I am trying to access internet via WiFi extender. When I am connecting via router no problems at all.
My friends also have E4GT, with stock EL29 firmware and modem, and they don't have any issues connecting over WiFi extender.
I tried other devices (iPhone 4S, iPod, laptops, netbook, etc.) those have no issues over WiFi extender either.
I tried just flashing the modem to EL29, FF02, FF18 and the results are the same as with FE22 (WiFi crashes and restarts on the phone).
Any remedy or anyone else having similar issues?
Click to expand...
Click to collapse
What kind of wi-fi extender are you using? And is it possible that it's the wi-fi configuration that is causing the problem?
Reason for asking is I have seen odd behavior with my work network on occasion, but the configuration is correct.

garwynn said:
What kind of wi-fi extender are you using? And is it possible that it's the wi-fi configuration that is causing the problem?
Reason for asking is I have seen odd behavior with my work network on occasion, but the configuration is correct.
Click to expand...
Click to collapse
I have the Diamond Multimedia WR300N WiFi Extender. The network is configured with WPA2 AES encryption (I tried using WPA & WEP as well).
Seems that only my E4GT has issues, like I said. My friends' pair of E4GTs with stock ROMs (EL29 and modem is also EL29) don't have any issues using my extender.

cp320703 said:
I have been on any number of roms/modems... In addition to my main one I have 3 routers flashed over to dd-wrt and used as repeaters throughout the house (yes, my wifi signal strength is EXCELLENT, EVERYWHERE!). I have never had any wifi connectivity problems nor have i seen this issue elsewhere on the forum before. Is it possible that a simple mistake is causing it, like a mistyped password saved as default?
Click to expand...
Click to collapse
No mistakes for sure, as I get the IP address on the smartphone, get max strength indicator on the phone. Tried WiFi Analyzer, it shows connected, and no problems (verified MAC address of the extender).
Again, the only time I am having the problems are when connected to the WiFi extender.
Could it be that the hardware for the phone's WiFi is older than my friends'? I got the phone back in November, through Walmart's subsidiary (they had a much cheaper price). Could it be that the phone itself is of "early" releases, and may have earlier hardware that Samsung switched away from later on?
Basically, I am trying to figure out if it's a hardware issue, and if it is, I can try to get it fixed/exchanged via Samsung's 1-year warranty or through Sprint.

KCRic said:
WiFi extender?? Are you talking about a repeater or an app?
I saw an app on the market claiming to 'extend' the wifi range of your phone. Obviously a bunch of bs. Hopefully that's not what you're talking about.
Click to expand...
Click to collapse
Diamond Multimedia WiFi extender WR300N, basically wireless repeater.

lindros_nyr said:
No mistakes for sure, as I get the IP address on the smartphone, get max strength indicator on the phone. Tried WiFi Analyzer, it shows connected, and no problems (verified MAC address of the extender).
Again, the only time I am having the problems are when connected to the WiFi extender.
Could it be that the hardware for the phone's WiFi is older than my friends'? I got the phone back in November, through Walmart's subsidiary (they had a much cheaper price). Could it be that the phone itself is of "early" releases, and may have earlier hardware that Samsung switched away from later on?
Basically, I am trying to figure out if it's a hardware issue, and if it is, I can try to get it fixed/exchanged via Samsung's 1-year warranty or through Sprint.
Click to expand...
Click to collapse
The driver changed with ICS so it could be a driver issue. It was a pain for me at work because I had to retweak my custom settings to get it to work again.
Here's a good test to verify: If your friends get the OTA and still can get on it's likely your phone. The only other thing you could try is the country code tweak in my wpa_supplicant.conf guide, which does seem to help sometimes.

garwynn said:
The driver changed with ICS so it could be a driver issue. It was a pain for me at work because I had to retweak my custom settings to get it to work again.
Here's a good test to verify: If your friends get the OTA and still can get on it's likely your phone. The only other thing you could try is the country code tweak in my wpa_supplicant.conf guide, which does seem to help sometimes.
Click to expand...
Click to collapse
Thanks for pointing it out. Just tried updating the wpa_supplicant.conf with ap_scan=2 and country=US. Saved it, tried to turn on WiFi radio, it wouldn't turn on. Tried restarting the phone, trying to enable WiFi radio, it won't come on. Finally deleted the file, was able to turn on the radio and OS basically rebuilt it, but of course without country code.
So, for this phone still no internet access via WiFi extender, but works like a charm with the router.

lindros_nyr said:
Thanks for pointing it out. Just tried updating the wpa_supplicant.conf with ap_scan=2 and country=US. Saved it, tried to turn on WiFi radio, it wouldn't turn on. Tried restarting the phone, trying to enable WiFi radio, it won't come on. Finally deleted the file, was able to turn on the radio and OS basically rebuilt it, but of course without country code.
So, for this phone still no internet access via WiFi extender, but works like a charm with the router.
Click to expand...
Click to collapse
For your case you may just want to try adding the country and not the ap_scan=2.
I need that for the old RADIUS configurations at work and is known to be twitchy at times.

garwynn said:
For your case you may just want to try adding the country and not the ap_scan=2.
I need that for the old RADIUS configurations at work and is known to be twitchy at times.
Click to expand...
Click to collapse
Yeah, I tried just country as well, and the WiFi radio wouldn't come on with it in the conf file.

lindros_nyr said:
Yeah, I tried just country as well, and the WiFi radio wouldn't come on with it in the conf file.
Click to expand...
Click to collapse
Hmm. That in itself shouldn't cause the wifi to fail on startup...
Can you please copy and paste your wpa_supplicant.conf information when you have time?
(Please remove any specific SSID, IDs and passwords though)
If you would feel more comfortable doing this by PM that's OK too.
Just have an odd feeling that there is something else at play here.

garwynn said:
Hmm. That in itself shouldn't cause the wifi to fail on startup...
Can you please copy and paste your wpa_supplicant.conf information when you have time?
(Please remove any specific SSID, IDs and passwords though)
If you would feel more comfortable doing this by PM that's OK too.
Just have an odd feeling that there is something else at play here.
Click to expand...
Click to collapse
After deleting the conf file, and enabling WiFi, the OS rebuilds it.
Basically this its' content...
Code:
update_config=1
ctrl_interface=wlan0
eapol_version=1
ap_scan=1
fast_reauth=1
p2p_listen_reg_class=81
p2p_listen_channel=1
p2p_oper_reg_class=81
p2p_oper_channel=11

lindros_nyr said:
After deleting the conf file, and enabling WiFi, the OS rebuilds it.
Basically this its' content...
Code:
update_config=1
ctrl_interface=wlan0
eapol_version=1
ap_scan=1
fast_reauth=1
p2p_listen_reg_class=81
p2p_listen_channel=1
p2p_oper_reg_class=81
p2p_oper_channel=11
Click to expand...
Click to collapse
Ok, I went back to GB EL29 stock rooted, reflashed modem to EL29, same problem - no internet connectivity via WiFi extender.
Flashed FF18 Sfhub's OTA rooted (with FF18 modem), installed Agat's emmc recompiled kernel. Still no internet connectivity via WiFi extender.
Anything else that I can do/try, or should I just get on Sprint's/Samsung's case and try to get it replaced by either Sprint (although I don't have insurance plan) or go through Samsung's warranty (had the device for about 7 months)?
Thanks!

Shot in the dark here, MAC filtering enabled somewhere?
Sent from my SPH-D710 using Tapatalk 2

dberend said:
Shot in the dark here, MAC filtering enabled somewhere?
Sent from my SPH-D710 using Tapatalk 2
Click to expand...
Click to collapse
No MAC filtering. Tried with Static IP and DHCP...
WiFi works when connected to router, when I move to the WiFi extender, it hops on to WiFi extender, full bars, WiFi analyzer confirms the signal strength. IP address and the rest of the network settings are correct. but no internet connectivity on the phone.

lindros_nyr said:
No MAC filtering. Tried with Static IP and DHCP...
WiFi works when connected to router, when I move to the WiFi extender, it hops on to WiFi extender, full bars, WiFi analyzer confirms the signal strength. IP address and the rest of the network settings are correct. but no internet connectivity on the phone.
Click to expand...
Click to collapse
Does the extender have a separate IP address or could it somehow be still trying to reach the router directly? You could try some ping tests to see how far that gets you, but if the repeater doesn't have a separate IP to route through I'm not sure it will get you anywhere.

garwynn said:
Does the extender have a separate IP address or could it somehow be still trying to reach the router directly? You could try some ping tests to see how far that gets you, but if the repeater doesn't have a separate IP to route through I'm not sure it will get you anywhere.
Click to expand...
Click to collapse
The WiFi extender basically is an access point to the router. Its' DHCP is off, but the phone gets IP address from the router.
Again my friends' E4GTs don't have any issues getting to the internet via my extender.

lindros_nyr said:
The WiFi extender basically is an access point to the router. Its' DHCP is off, but the phone gets IP address from the router.
Again my friends' E4GTs don't have any issues getting to the internet via my extender.
Click to expand...
Click to collapse
Well if you're able to connect and obtain an IP address then I can't think of any reason why the traffic would not go through instead of a potential routing issue - at a hardware level it is communicating. Higher up in the process I could see a potential issue with routing if it is trying to route directly to the router and not through the extender.
I would try this test if you're wiling - enable DHCP on the extender, treat the extender as a subnet. This should require the repeater to get its IP address where you may be able to do a ping test and see where the traffic is being stalled. You could also try changing the SSID when contacting via the extender if it would allow. Honestly, any way for it to know more clearly which is which may help resolve your problem.

garwynn said:
Well if you're able to connect and obtain an IP address then I can't think of any reason why the traffic would not go through instead of a potential routing issue - at a hardware level it is communicating. Higher up in the process I could see a potential issue with routing if it is trying to route directly to the router and not through the extender.
I would try this test if you're wiling - enable DHCP on the extender, treat the extender as a subnet. This should require the repeater to get its IP address where you may be able to do a ping test and see where the traffic is being stalled. You could also try changing the SSID when contacting via the extender if it would allow. Honestly, any way for it to know more clearly which is which may help resolve your problem.
Click to expand...
Click to collapse
Thank you for providing assistance with this issue. I did the setup as you mentioned to no avail. Everything works fine as long as it's not in the repeater mode. Can't do a repeater configuration with a different SSID, though.
Also, tried turning the router off, and hooking up the extender via LAN cable to the cable modem, and configuring the WiFi extender as a "WiFi router". Everything was working again.
I came to the conclusion, that it's either the driver or the hardware, although the driver alone shouldn't be an issue, as I mentioned, we tested it with 2 other E4GTs on the same firmware & modem versions, and they didn't encounter any issues.
I went to Sprint store, paid $35 and should be getting a replacement phone under warranty shortly.
Will let you know how I make out.
Again thank you for all of your help!

[Q] Wifi keeps getting stuck on "authenticating"

Pretty much every time I try to connect to my home wifi, it keeps getting stuck on authenticating then it will fail and do it over again and again until it says network disabled, poor connection, even though it has a full 4 bars... I've tried turning it off and back on, I've tried forgetting it and redoing it, I've tried restarting the phone.. The only thing that seems to work is for me to unplug my router and plug it back in while leaving the wifi on my phone on. When the router boots back up, then my phone will connect. I would say it's something wrong with my router, but my other phone has absolutely no problem connecting.
Any help would be appreciated. Thanks
Edit: Oh yeah, the phone WILL connect if I turn the password off on my router. I am 100% sure I'm putting the correct password in on my phone, I've checked it numerous times, plus as I said, the phone will connect if I reboot the router every single time I want to connect, so the password is definitely correct.

What ROM are you using?
Sent from my SAMSUNG-SGH-T989 using xda premium

skaroger867 said:
What ROM are you using?
Sent from my SAMSUNG-SGH-T989 using xda premium
Click to expand...
Click to collapse
Originally I was using the stock ROM on 4.0.4, now I'm using the most current CM9 nightly. Have the same problem on both ROMs.

Found a solution, set up my router so that the security is disabled, but so that only the mac addresses I allow can get through. Works perfect and no loss of security.

MAC Address Filtering is NOT secure!
SurgeRush said:
Found a solution, set up my router so that the security is disabled, but so that only the mac addresses I allow can get through. Works perfect and no loss of security.
Click to expand...
Click to collapse
One could easily listen on your network to scrape your MAC address, and then spoof it. I suppose one could brute-force WPA encryption too, but it's much harder.

You can always just set a static ip. Tap and hold the wifi network and tap advanced and change dhcp to static and go on your pc and find your ip by launching cmd and enter ipconfig. Then enter the info cmd gives you onto your phone but to avoid ip conflicts just change the end of the ip address to something else like 84 no devices usually use that.

Ive seen that issue attempting to connect to my own wifi a couple of times, and in every case it was caused by the wrong PW. I would reset the PW on your router so you know exactly what it is. they are case-sensitive so it could be that you mistyped a letter or two on either the router or your phone. you should also be able to connect using WDS iirc, assuming the router supports it (most newer routers do)

Galaxy Note 2 Wifi issue

This is pretty strange so I thought I'd check here with people.
I got my new Sprint Note 2 today. When I was at home it connected to my wifi network and worked fine. When I got to work I connected it to our wifi network and the internet won't work. If I turn off wifi internet comes back.
Here's the kicker, I have my old iPhone right next to it connected to the work wifi network and it is connected fine to the internet. This is definitely going through wifi as I no longer have a data plan on that phone.
I checked with our IT admin who said that there is no need to "accept" a device on our wifi network. He also rebooted the network for good measure. After both phones lost the network (from the reboot) and reconnected the same thing happened. No internet from my Note but internet works fine on the iPhone. Restarting my Note doesn't fix the problem.
Any ideas? Thanks.

I have the same problem. Need help too.
Sent from my GT-N7100 using xda app-developers app

ks-man said:
This is pretty strange so I thought I'd check here with people.
I got my new Sprint Note 2 today. When I was at home it connected to my wifi network and worked fine. When I got to work I connected it to our wifi network and the internet won't work. If I turn off wifi internet comes back.
Here's the kicker, I have my old iPhone right next to it connected to the work wifi network and it is connected fine to the internet. This is definitely going through wifi as I no longer have a data plan on that phone.
I checked with our IT admin who said that there is no need to "accept" a device on our wifi network. He also rebooted the network for good measure. After both phones lost the network (from the reboot) and reconnected the same thing happened. No internet from my Note but internet works fine on the iPhone. Restarting my Note doesn't fix the problem.
Any ideas? Thanks.
Click to expand...
Click to collapse
Is the wi-fi sleep mode on?

Very odd. I've had no such problem at home,work or university
Sent from my GT-N7100 using xda premium

My network admin created a second wifi network to connect to (I guess our router supported it) and when I connected to the new one I got internet.
If it helps others try and solve the issue he tried pinging the IP address that my phone was using and said that he could only send information but not get anything back.

ks-man said:
This is pretty strange so I thought I'd check here with people.
I got my new Sprint Note 2 today. When I was at home it connected to my wifi network and worked fine. When I got to work I connected it to our wifi network and the internet won't work. If I turn off wifi internet comes back.
Here's the kicker, I have my old iPhone right next to it connected to the work wifi network and it is connected fine to the internet. This is definitely going through wifi as I no longer have a data plan on that phone.
I checked with our IT admin who said that there is no need to "accept" a device on our wifi network. He also rebooted the network for good measure. After both phones lost the network (from the reboot) and reconnected the same thing happened. No internet from my Note but internet works fine on the iPhone. Restarting my Note doesn't fix the problem.
Any ideas? Thanks.
Click to expand...
Click to collapse
Try changing your wifi channel config in the router.

Hi, I've got the International version N7100 and experiencing weird wifi problem. I have tried to reset my wifi router and use static IP but it doesn't solve the problem. Btw, the problem is whenever I connect my Note 2 to wifi it would lose connection after a while then messes my router and connection of my PC to router as well. Never had this issue until I brought the Note 2 home a week ago. I had to restart my router and turn off my wifi on Note 2 for everything else to work. My iPad, iPhone and PC are all doing fine when Note 2's wifi is off.

I used to have terrible problems with my Virgin Superhub which all went away when I changed the security settings to WEP hexidecimal from WPA2-PSK (AES). Laptops and phones would have intermittent connections all the time which a reboot or channel change would sort out but only temporarily. Give it a whirl.
Sent from my GT-N7100 using xda app-developers app

I've been experiencing the same problem. It's especially annoying when I try to download big size apps on Google Play ( > 1 gb) because it will stop any moment and i will have to re-download it over and over again. It never happens when I connect to school wifi but it just happens when I connect to my wifi at home. Weird. Nothing is wrong with my wifi at all because my other computer is always connected 24/7 without any problem.

I have a similar problem on Omega Ron v5.0 with latest Andrei kernel. The phone gets stuck sometimes in getting IP address part or have disconnects. It's annoying.
Regards
GT-N7100 cihazımdan Tapatalk 2 ile gönderildi

quick reset of router and modem does wonders!

boodies said:
quick reset of router and modem does wonders!
Click to expand...
Click to collapse
Afraid not.
I did that after other efforts failed but still have to go through same issue every now and then. This is not a permanent problem but something that occurs at least once a day for me.

Also having Wifi issues with GN2 from Sprint
I got the GN2 on it's release date (this past Thursday) through Sprint. Got it home got set up, connected...everything worked beautifully.
After a couple of hours, downloading apps etc. I noticed it had stalled. Turned off WiFI and used the network to finish. Turned back on WiFi and Voila, action again, but a few hours later it stalled.
I first made sure all of my settings were in agreement. No sleep mode or anything like that was enabled. No power saver either.
Couple hours goes by, WiFi connectivity stalls (even though it shows a full signal) I contacted TWC and made sure it wasn't the modem/router. I changed the wifi channel, tinked with the bandwidth... everything worked...an hour later it stalled. Called Sprint they said I had a dud, took it back, exchanged it, got the new one... SAME ISSUES. YEsterday I connected to my Church network HOPING it was an issue at home, but not so. After an hour on the network it stalled.
Contacted Samsung today and they have had no complaints according to them so i said I'm happy to be the first... If anyone finds a fix please let me know.
PD

PastorDroid said:
Contacted Samsung today and they have had no complaints according to them so i said I'm happy to be the first... If anyone finds a fix please let me know.
PD
Click to expand...
Click to collapse
Do you have any solution yet? I have the same issues with 2 different networks. I already contacted Samsung, but they only say I should do a reset of my device and read the setup instuctions for wifi. I'm still in contact with Samsung and hardly try to get a solution.
Stay tuned, I'll post any news I can get.

jetsetwilly said:
I used to have terrible problems with my Virgin Superhub which all went away when I changed the security settings to WEP hexidecimal from WPA2-PSK (AES). Laptops and phones would have intermittent connections all the time which a reboot or channel change would sort out but only temporarily. Give it a whirl.
Sent from my GT-N7100 using xda app-developers app
Click to expand...
Click to collapse
I'd prefer it to work with the stronger encryption of WPA2 rather than WEP.

OP: it will be great if you could add a poll to the thread as that way we can see whats the percentage of users are experiencing this issue,
Thanks
Sent from my GT-I9300 using xda premium

ks-man said:
This is pretty strange so I thought I'd check here with people.
I got my new Sprint Note 2 today. When I was at home it connected to my wifi network and worked fine. When I got to work I connected it to our wifi network and the internet won't work. If I turn off wifi internet comes back.
Here's the kicker, I have my old iPhone right next to it connected to the work wifi network and it is connected fine to the internet. This is definitely going through wifi as I no longer have a data plan on that phone.
I checked with our IT admin who said that there is no need to "accept" a device on our wifi network. He also rebooted the network for good measure. After both phones lost the network (from the reboot) and reconnected the same thing happened. No internet from my Note but internet works fine on the iPhone. Restarting my Note doesn't fix the problem.
Any ideas? Thanks.
Click to expand...
Click to collapse
I had this issue with my S3, but never with the Note 2. What i did in that instance was reinstall the OS and that seemed to have fixed the issue. Hope this helps!
Sent from my iPad using Tapatalk HD

Same issue here. Connect wifi and I'm able to hold connection for as little as minutes at times. Turn back on 4G and I'm fine. If I re enable wifi straight after it works intermittently. This is true of both my home and office wifi. So I'm lead to believe it's the phone.

Hi,
Almost the same thing here. everytime I go out of my home and comeback the wifi network seems to work but no internet access. I have to stop and restart wifi then it works.
very strange issue. ok I have a work around but I'm going to open a ticket to Samsung.

Same issue - connects for about 30 seconds
I've tried on different routers. Other devices (iphone, ipad, S3, etc.) all work fine. Sees the wifi network. connects, then disconnects and TURNS OFF WIFI. I can't figure out how to go to service mode to see if this is a timer issue. I've tried on both G and N networks. using a verizon fios, actionteck router (and netgear). Also, will not remember the password credentials. tried router reboot and fidling, etc. Driving me nuts. any suggestions ???

Cannot connect to WiFi

Is anyone else having issues connecting to wifi? When I try to connect to wifi at my house, I get a pop-up error saying "AP currently not in use. Internet connection slow." If I click retry, it comes up again. If I click cancel, it says "Failed to obtain IP" and is not connected.
I have tried restarting my model/router with no luck. My Note 3, laptop, and other devices have no problem connecting to this wifi network...

I had a problem with wifi,but sounds different then your issue.Mine would just disable after obtaining ip.Samsung rep at best buy reflashed phone.That saved all data and apps.AND,it fixed wifi.If you can't work thru your issue,go to best buy or att store and get it reflashed.Cant hurt.
Good luck.
Sent from my SAMSUNG-SM-N910A using XDA Free mobile app

OK, so went to the ATT store today and they reflashed my phone. Got home just now and tried to connect to wifi, same issue
Is anyone else having this problem?

Fixed it.
SOLUTION: I changed my router encryption type from WEP to WPA and now it works no problem

Try rebooting your router, I had the same issue the first day I got mine and a reboot fixed it.

zaures said:
Try rebooting your router, I had the same issue the first day I got mine and a reboot fixed it.
Click to expand...
Click to collapse
GReddySetGO said:
I have tried restarting my model/router with no luck. My Note 3, laptop, and other devices have no problem connecting to this wifi network...
Click to expand...
Click to collapse
This is a forum, please read. At the very least, read the OP if you're going to post something....
Anyway, already solved.

GReddySetGO said:
Fixed it.
SOLUTION: I changed my router encryption type from WEP to WPA and now it works no problem
Click to expand...
Click to collapse
Your neighbors are going to be pissed. They can't steal your wireless any more.
Seriously... You did yourself a favor... WEP = ROFL stupidity for wireless networks.
-----
Sent with my Galaxy Note 4

GReddySetGO said:
Fixed it.
SOLUTION: I changed my router encryption type from WEP to WPA and now it works no problem
Click to expand...
Click to collapse
No go for me I just Got my N4 from Verizon last monday and having the same issue u had. I changed my encryption from wep to wap and still same problem. Ima go to a verizon store and see if the "reflash" the phone like some suggest here. Might help my problem

Hi all,
I also experience the same issue from time to time. I have this happen on both my home network (WPA2-Personal) and work (WPA2-Enterprise). My fix is to either reboot the phone or activate Airplane Mode for about 20 seconds and then disable Airplane Mode. After doing that, wifi picks right up for me. YMMV.
I can try to get the exact error log messages from our networking technician at work if it would be helpful to anyone.
Out of curiosity, do any of you have other peripherals connected at the time you experience the issue (Pebble Watch, etc.)?

Same issue
With my GN4, I can connect to my home WIFI no problem and my GF's WIFI no problem but when I go to my Dad's, I CANNOT connect to his WIFI (Netgear WTG624v3) but both of my sisters with a Samsung Tab 3 and Samsung S4 CAN connect to my Dad's WIFI. It's really aggravating. Basically, when I try to connect, it says "connecting" "saved" Then it says "scanning", and says "connecting" "saved" again and again ..... But never connects.
I have tried changing just about every WIFI setting on his router including resetting the router. Tried removing the encryption making an "Open" network and STILL can't connect... and tried every encryption type provided and still nothing. I set the dynamic address range from .4 to .254 (on router) so I could try connecting with a static address to 192.168.1.2 / .3 and still nothing. I tried removing my GN4 browser cache, and setting it to airplane mode(20 secs)... nothing.
I'm at a loss.. given that both of my sisters with two different devices can connect to my Dad's WIFI but I can't with my GN4? But I can connect my GN4 to other WIFI networks, no prob.
UPDATE: Next, I will try downgrading the firmware version on the router to an earlier version. Hopefully, that's the solution. I will report my findings here.

Downgrading or using an older Firmware version for this Netgear WTG624v3 router DID THE TRICK!
If anyone else is having the inability to log into a WIFI router, try installing an older router Firmware version. I got the idea from here:
https://discussions.apple.com/thread/4564251?start=0&tstart=0