Galaxy S4 3G/4G weird issues

[Dylad]

Hi guys,

I have a Galaxy S4 with KitKat 4.4.2. I am having some issues with signal that I don't understand, and neither do the more knowledgeable people at my local Verizon store.

When I have the 4G or 3G icon and a few bars of signal strength in white, all is fine. When the bars and icon go grey, I can no longer send or receive texts or load up a webpage, but can make a call and have it immediately go through. The phone will bounce between grey and white constantly while simply sitting at my desk at work, and I can 'lose' connection for several hours sometimes. Restarts or toggling Airplane mode on/off can sometimes fix this. Other times I'll just have to wait until I get in my car and get a quarter mile or so away from work before it realizes that it's a phone and it can connect to things again.

Along the same lines, I'll have one or two bars of 4G and be loading webpages, and then I'm assuming it tries to grab a different tower suddenly and I drop down to one or two bars of 3G, greyed out, and lose data connection on whatever I was doing. I have to try to toggle airplane mode on/off to 'force' it to find the 4G signal again. I'm not physically moving around when this happens, and there really isn't any equipment that could be causing interference. My coworker has an older Droid Razr Maxx and you can sit the phones side by side and his doesn't do this.

I never drop a call or have a scenario where it will not place a call because of this, but the data connection is infuriatingly unstable for no reason that I can see.

 

[Ollie]

Did they do a factory data reset on the device in the store?

It sounds like either your modem firmware is corrupted or the modem itself is on its way out.

 

[Dylad]

They did not, but recommended it. I have to spend a significant amount of time pulling off important data before I can do that, so I figured before I started, I'd ask the question here. I lurk here often and this is the first problem I can't solve through old posts. (Which means I know I really have to do a reset to proceed further but was hoping against hope for an easy fix!)

Thanks for your help.

 

[Ollie]

Yeah doing an FDR is usually not a decision that ever feels good. There is usually a lot that has to be done prior and then after just to see if it provides a fix. Especially if you aren't rooted.

Samsung Kies can do most of the heavy work for you.

If you use an SDcard be sure to pull it out before the FDR.

 

[KaosMaster]

You definitely need to FDR the device...But I am thinking your gonna need to flash the software as well. I would back up everything and reload the software using the software repair assistant from Verizon then FDR after that as well