[Q] Any rom- any modem - shows I have signal, but intermittently no calls or texts

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KnowledgeBroker

Senior Member
Sep 7, 2010
1,618
731
Daytona Beach, Fl
Samsung Galaxy S8+
Firstly, I'm not a noob.
Secondly, I've even opened the phone to see if there is anything loose.. I used to repair phones, and hardware wise everything looks fine. Plus, the issue can happen while the phone is just sitting there, it isn't caused by the phone being moved that I can tell.
So I might suddenly have a voicemail show up, because my phone didn't have signal. Or if I call out, it never gives an error of any kind, it just doesn't ring.. same idea with text, sometimes they just come in all at once.

But the whole time, it SHOWS I have signal. If I search for networks(Settings>more>networks>available networks) when I have no issues, it searches, and shows US or AT&T(which is odd since I have tmobile, but whatever).. if I do this while I AM having the issue - it doesn't search, and nothing shows. Hitting search doesn't do anything.
If I put into airplane mode and take it back out, it will show no signal until the problem goes away. Restarting the phone doesn't appear to solve the issue.

I'm at a total loss here. I've searched - a LOT. This is kind of a hard issue to search for, haven't seen anyone else describe something similar.. so I am just throwing this out here, hoping someone might have some thoughts?
 

MrAlez

Senior Member
May 5, 2013
184
41
Firstly, I'm not a noob.
Secondly, I've even opened the phone to see if there is anything loose.. I used to repair phones, and hardware wise everything looks fine. Plus, the issue can happen while the phone is just sitting there, it isn't caused by the phone being moved that I can tell.
So I might suddenly have a voicemail show up, because my phone didn't have signal. Or if I call out, it never gives an error of any kind, it just doesn't ring.. same idea with text, sometimes they just come in all at once.

But the whole time, it SHOWS I have signal. If I search for networks(Settings>more>networks>available networks) when I have no issues, it searches, and shows US or AT&T(which is odd since I have tmobile, but whatever).. if I do this while I AM having the issue - it doesn't search, and nothing shows. Hitting search doesn't do anything.
If I put into airplane mode and take it back out, it will show no signal until the problem goes away. Restarting the phone doesn't appear to solve the issue.

I'm at a total loss here. I've searched - a LOT. This is kind of a hard issue to search for, haven't seen anyone else describe something similar.. so I am just throwing this out here, hoping someone might have some thoughts?
did your efs changed?
cause if you have generic imei that should be the problem
 

KnowledgeBroker

Senior Member
Sep 7, 2010
1,618
731
Daytona Beach, Fl
Samsung Galaxy S8+
did your efs changed?
cause if you have generic imei that should be the problem

I clearly said that I can receive calls and texts.. just not all the time. I had a problem with my EFS a long time ago, but was able to fix it, my IMEI is good, and I can't see any issue in my phone information(including serial, etc). As I said, this is an intermittent problem- right now I would say the issue only happens 20% of the time, maybe less.
It isn't often, but I have had multi-hour phone calls, and none have ever been disconnected by this issue, tho I feel like if I wasn't on the phone the issue would have happened at some point..
Let me point out that this has been going on over two months - in that time I have used stock roms, slim roms, every rom and android version from 4.1-4.4 and many kernels - none seemed to remotely effect the issue.

Is there a possibility of some strange modem thing? My friend has the us variant of the s3, and he has read that he can't downgrade his modem.. so I've avoided using any early modems just in case.. our phone seems to have less and less updated threads for things like modems.
 

MrAlez

Senior Member
May 5, 2013
184
41
I clearly said that I can receive calls and texts.. just not all the time. I had a problem with my EFS a long time ago, but was able to fix it, my IMEI is good, and I can't see any issue in my phone information(including serial, etc). As I said, this is an intermittent problem- right now I would say the issue only happens 20% of the time, maybe less.
It isn't often, but I have had multi-hour phone calls, and none have ever been disconnected by this issue, tho I feel like if I wasn't on the phone the issue would have happened at some point..
Let me point out that this has been going on over two months - in that time I have used stock roms, slim roms, every rom and android version from 4.1-4.4 and many kernels - none seemed to remotely effect the issue.

Is there a possibility of some strange modem thing? My friend has the us variant of the s3, and he has read that he can't downgrade his modem.. so I've avoided using any early modems just in case.. our phone seems to have less and less updated threads for things like modems.
Actually, you can change your modem, but if you went to the 4.3 version of touchwiz, try using other modem from another 4.3 tw, you can give a try, but dont use a 4.1 or 4.2 modem, just a 4.3 modem, (efs2)
 

KnowledgeBroker

Senior Member
Sep 7, 2010
1,618
731
Daytona Beach, Fl
Samsung Galaxy S8+
Actually, you can change your modem, but if you went to the 4.3 version of touchwiz, try using other modem from another 4.3 tw, you can give a try, but dont use a 4.1 or 4.2 modem, just a 4.3 modem, (efs2)

I think that was when I had my original efs issue - I was unaware about not going down below 4.3 again- but like I said, that was fixed. Or at least I think it was.
Is there a process to going to efs1 type partition? Perhaps if I properly go back to the original type.. and then upgrade properly(all after backing up my EFS of course..)

I guess the real issue is- could this be related to my problem AT ALL? I mean I get reception most of the time(guessing80%+), and it doesn't even show a signal loss when I can't find a network operator by manually searching!
I guess another thing that has me curious - it shows US or AT&T as the network operators, even tho I am on tmobile(not even pre-paid or anything).. if I select US it works, if I select automatic, it works, if I select AT&T it says your sim card doesn't allow you to register on this network..?

I'm just at a loss, because it doesn't seem like a hardware issue.. I'm actually on the phone with tmobile at the moment trying to see if MAYBE it is something on their side, how they have me registered on the network.. something!
 
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MrAlez

Senior Member
May 5, 2013
184
41
I think that was when I had my original efs issue - I was unaware about not going down below 4.3 again- but like I said, that was fixed. Or at least I think it was.
Is there a process to going to efs1 type partition? Perhaps if I properly go back to the original type.. and then upgrade properly(all after backing up my EFS of course..)

I guess the real issue is- could this be related to my problem AT ALL? I mean I get reception most of the time(guessing80%+), and it doesn't even show a signal loss when I can't find a network operator by manually searching!
I guess another thing that has me curious - it shows US or AT&T as the network operators, even tho I am on tmobile(not even pre-paid or anything).. if I select US it works, if I select automatic, it works, if I select AT&T it says your sim card doesn't allow you to register on this network..?

I'm just at a loss, because it doesn't seem like a hardware issue.. I'm actually on the phone with tmobile at the moment trying to see if MAYBE it is something on their side, how they have me registered on the network.. something!

Bro like the said says "Once you go black, you never go back" lol jk, i read somewhere that once you go efs2 is difficult to go to efs1 you will face "UNKNOWN NETWORK", the only thing you left to do is, restore to stock tmobile, root, use triangle away, unroot, flash again stock, and go to your network operator and tell them what problem you have, i think it my be a problem with the network problem idk more, im out of ideas, you should try that. thanks for reading
 

RazorMC

Senior Member
Feb 12, 2011
426
96
SiN CiTY
...
I'm at a total loss here. I've searched - a LOT. This is kind of a hard issue to search for, haven't seen anyone else describe something similar.. so I am just throwing this out here, hoping someone might have some thoughts?

Had this issue when I installed KK rom after stock 4.3
Fixed it with patched mg4 modem.
 

KnowledgeBroker

Senior Member
Sep 7, 2010
1,618
731
Daytona Beach, Fl
Samsung Galaxy S8+
Had this issue when I installed KK rom after stock 4.3
Fixed it with patched mg4 modem.

So you're sure you were having an issue just like mine? I've read dozens and dozens of threads for tons of samsung devices.. I recall one of them talking about patched modems - any chance you can post the link or even upload a flashable? If this turns out to be a fix.. you will be a god among men!
 

RazorMC

Senior Member
Feb 12, 2011
426
96
SiN CiTY
So you're sure you were having an issue just like mine? I've read dozens and dozens of threads for tons of samsung devices.. I recall one of them talking about patched modems - any chance you can post the link or even upload a flashable? If this turns out to be a fix.. you will be a god among men!

Yeah more or less what you were facing. Internittent network drops.
Dropbox link for patched MG4

Let me know if it worked out.

PS: If that doesn't work, then you can also try a modem for your region. Currently using NA8 right now and no issues shifting between stock 4.3 and KK Roms
 
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KnowledgeBroker

Senior Member
Sep 7, 2010
1,618
731
Daytona Beach, Fl
Samsung Galaxy S8+
Yeah more or less what you were facing. Internittent network drops.
Dropbox link for patched MG4

Currently using NA8 right now and no issues shifting between stock 4.3 and KK Roms

Let me know if it worked out.

I'll definitely give it a try.. where is the source you found it from, how did you figure it out? I found this emergency zip uploaded by justarchi that looks like a patched modem.. is this it? http://xdaforums.com/showpost.php?p=43946365&postcount=15
Otherwise, for curiosities sake, if you figured this out(and it does fix my issue), I am QUITE curious how you figured it out!
 

RazorMC

Senior Member
Feb 12, 2011
426
96
SiN CiTY
I'll definitely give it a try.. where is the source you found it from, how did you figure it out? I found this emergency zip uploaded by justarchi that looks like a patched modem.. is this it? http://xdaforums.com/showpost.php?p=43946365&postcount=15
Otherwise, for curiosities sake, if you figured this out(and it does fix my issue), I am QUITE curious how you figured it out!

I found it on xda long ago. But since it took ages to find the link, I bookmarked the link so I could post without having to spend hours scouring threads for it. It was originally in the modem/baseband thread.

AFAIK, JustArchi was referring to old modems no longer working with stock 4.3 firmwares and the resulting corrupted IMEIs when you use old modems or tried to go back to 4.1.2.

This post on my thread recommended patched MK6 kernel + patched MK6 modem.
But I went with just patched MG4 and worked. The issue at that time was no network, but I've been able to resolve network drops with patched modem.

This is just my experience though.

Before you flash the modem, make a backup in PhilZ Recovery first. Backup efs and modem both.