[Q] Galaxy S2 unable to register to network, no signal - Galaxy S II Q&A, Help & Troubleshooting

Hi,
I'm facing this major problem with my handset.
When I insert a SIM card to my mobile, it registers with the network (VODAFONE IN) with signal strength of 12asu and then gradually decreases to 5asu and then 1asu when my phone shows no signal afterwards. The carrier is shown as Unknown and service as out of service.
If I put the same SIM in another phone, it works. So no problem with the SIM or Network.
I have tried the following:
1) Flashed various modems
2) Flashed various ROMS (CM9, CM10, Official Stock)
3) Did complete WIPE. Factory Reset, Clear cache, Clear Dalvik cache, Format /system
4) I also restored by efs to a backup I had of my efs(taken when I first got the phone in 2011).
5) Also used Repair Galaxy S2 app which basically fixes RW permissions of the EFS folder.
6) Also used EFS Pro to repair my .nav files
7) Also used GetRIL tool to check if the drivers are matching.
Even after doing everything, the problem is same. When I first insert the sim card, it gets signal for around 5 minutes and then suddenly it goes to 1asu with no signal forever. I also kept my phone as it is for one whole day, but nothing: my phone is unreachable and there's no signal.
I had never dropped my phone and possibility of any physical damage to the receiver is very low.
The only reason I can see is this:
I was on DilDroid ICS and everything was fine until one day, I went to Recovery and fixed permissions. (Btw, DilDroid ICS used Siyah kernal)
And I think that was the last thing I did after which my phone couldn't receive signals.
I think some files have been corrupted and even after factory reset etc. it remains and the next time I flash another ROM, the files are still there.
Can someone tell me a way to completely clean my galaxy s2 and then start off by flashing a new ROM.
Or any other solution. Kindly help.

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deathfrag said:
Hi,
I'm facing this major problem with my handset.
When I insert a SIM card to my mobile, it registers with the network (VODAFONE IN) with signal strength of 12asu and then gradually decreases to 5asu and then 1asu when my phone shows no signal afterwards. The carrier is shown as Unknown and service as out of service.
If I put the same SIM in another phone, it works. So no problem with the SIM or Network.
I have tried the following:
1) Flashed various modems
2) Flashed various ROMS (CM9, CM10, Official Stock)
3) Did complete WIPE. Factory Reset, Clear cache, Clear Dalvik cache, Format /system
4) I also restored by efs to a backup I had of my efs(taken when I first got the phone in 2011).
5) Also used Repair Galaxy S2 app which basically fixes RW permissions of the EFS folder.
6) Also used EFS Pro to repair my .nav files
7) Also used GetRIL tool to check if the drivers are matching.
Even after doing everything, the problem is same. When I first insert the sim card, it gets signal for around 5 minutes and then suddenly it goes to 1asu with no signal forever. I also kept my phone as it is for one whole day, but nothing: my phone is unreachable and there's no signal.
I had never dropped my phone and possibility of any physical damage to the receiver is very low.
The only reason I can see is this:
I was on DilDroid ICS and everything was fine until one day, I went to Recovery and fixed permissions. (Btw, DilDroid ICS used Siyah kernal)
And I think that was the last thing I did after which my phone couldn't receive signals.
I think some files have been corrupted and even after factory reset etc. it remains and the next time I flash another ROM, the files are still there.
Can someone tell me a way to completely clean my galaxy s2 and then start off by flashing a new ROM.
Or any other solution. Kindly help.
Click to expand...
Click to collapse
do a full wipe and install another rom and see
1) Wipe data/Factory reset
2) go to 'mounts and storage' and wipe data and system there.
3)wipe Cache partition as well as Dalvik in advance.
then install the rom zip file
and again do all wipes except system and then check for issue's
ps- before that try with a different netwrk sim on the phone and see if the issue persists or not

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Sun90 said:
do a full wipe and install another rom and see
1) Wipe data/Factory reset
2) go to 'mounts and storage' and wipe data and system there.
3)wipe Cache partition as well as Dalvik in advance.
then install the rom zip file
and again do all wipes except system and then check for issue's
ps- before that try with a different network sim on the phone and see if the issue persists or not
Click to expand...
Click to collapse
Hi Sun90,
I've tried flashing different ROM after complete wipe. I also wiped system. But never wiped data. Doing it now.
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update:
I tried your approach, but still facing the same problem. Please help.

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Hello everyone.
I got exactly the same problem. I had my I9100 for over a year. I flashed lots of roms. Now i got this problem. I cannot connect to the service of my carrier. I got realy bad connection or no connection at all. The sim works on different Galaxys and its not a problem with the apn and or my IMEI. Evereything is ok there.
what have I done so far:
flashed several roms
flashed several modems
went back to original rom
several whipes
Now I have a nice MP3 player with some WIFI at home
What im thinkin about could be the problem but I dont know how to fix it:
I think i got a wrong CSC and there is something rotten with my partitions...

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deathfrag said:
Hi Sun90,
I've tried flashing different ROM after complete wipe. I also wiped system. But never wiped data. Doing it now.
-----
update:
I tried your approach, but still facing the same problem. Please help.
Click to expand...
Click to collapse
Aton88 said:
Hello everyone.
I got exactly the same problem. I had my I9100 for over a year. I flashed lots of roms. Now i got this problem. I cannot connect to the service of my carrier. I got realy bad service or no service at all. The sim works on different Galaxys and its not a problem with the apn.
what have I done so far:
flashed several roms
flashed several modems
went back to original rom
several whipes
Now I have a nice MP3 player with some WIFI at home
Click to expand...
Click to collapse
have u guys tried with a differnet netwrk's Sim other than the one ur into and checked for the same issue?

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Sun90 said:
have u guys tried with a differnet netwrk's Sim other than the one ur into and checked for the same issue?
Click to expand...
Click to collapse
Haven't tried that, but what will that prove? My SIM works perfectly okay on different mobile.

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Sun90 said:
have u guys tried with a differnet netwrk's Sim other than the one ur into and checked for the same issue?
Click to expand...
Click to collapse
yes i tried another networks's sim as well. sim was recognised. sim-pin ok. but no service/connection. on manual carrier choice the galaxy said something like connected to service. but there is no internet and if i try to make a call there is the "no service" popup again.
i dont think its a problem with the HW because sometimes i see the different carriers. i just cannot connect to them!
as I said before: I think its a SW problem around CSC and/or somethin is ****ed up with my phones partitions...

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Aton88 said:
yes i tried another networks's sim as well. sim was recognised. sim-pin ok. but no service/connection. on manual carrier choice the galaxy said something like connected to service. but there is no internet and if i try to make a call there is the "no service" popup again.
i dont think its a problem with the HW because sometimes i see the different carriers. i just cannot connect to them!
Click to expand...
Click to collapse
That's true. If I sometime connect to my network, I can quickly make a call & for the duration of the call, it remains okay. Pretty strange. I can goto flight mode and then back and sometimes I get the signals back for around 2-3 minutes before again going to no signal.
@Aton88, Were you by any chance on Siyah kernal or DilDroid ROM or went outside India? Just asking. Trying to find a pattern here.

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deathfrag said:
Haven't tried that, but what will that prove? My SIM works perfectly okay on different mobile.
Click to expand...
Click to collapse
rather trying to know whether it prove a thing' isn't of much importance compared to giving it a try and see for any hardware issue

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Sun90 said:
rather trying to know whether it prove a thing' isn't of much importance compared to giving it a try and see for any hardware issue
Click to expand...
Click to collapse
That's true, I'll try that with my friend's SIM tomorrow. Sorry, I didn't mean to offend you.

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deathfrag said:
That's true, I'll try that with my friend's SIM tomorrow. Sorry, I didn't mean to offend you.
Click to expand...
Click to collapse
yeh sure, give it a try
and by the way creating more threads for the same issue doesn't bring about any goodthing to u for sure, hence stick to the rules of XDA, rather than doing this and getting Infracted by the mods for the same
take my words this is for ur own good

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Sun90 said:
yeh sure, give it a try
and by the way creating more threads for the same issue doesn't bring about any goodthing to u for sure, hence stick to the rules of XDA, rather than doing this and getting Infracted by the mods for the same
take my words this is for ur own good
Click to expand...
Click to collapse
Thanks for the advice. I shall make sure I don't create duplicate threads. Btw, I even checked if my phone is locked but it's not. Everything is OFF.
I even checked the validity of my IMEI and it seems to be valid.
I'm really running out of ideas to check what's wrong.

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I tried a different provider's SIM and even that doesn't work.
Can someone tell me how to do a complete clean install.
Are these steps complete or any steps are missing:
1. Factory Reset
2. Clear cache
3. Clear Dalvik Cache
4. Clear Battery stats
5. Wipe /system
6. Wipe /data
Then Goto Odin: Flash the official Stock Firmware for India.
Am i missing anything? I want a complete WIPE, so that no previous corrupted files are present. Please help.

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deathfrag said:
I tried a different provider's SIM and even that doesn't work.
Can someone tell me how to do a complete clean install.
Are these steps complete or any steps are missing:
1. Factory Reset
2. Clear cache
3. Clear Dalvik Cache
4. Clear Battery stats
5. Wipe /system
6. Wipe /data
Then Goto Odin: Flash the official Stock Firmware for India.
Am i missing anything? I want a complete WIPE, so that no previous corrupted files are present. Please help.
Click to expand...
Click to collapse
u can give it a try with those steps but no4 is not necessary

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i have a similar problem.....in the about section my network is displayed correctly but under "service state" it says out of service... BUT the internet works fine....when i try to make a call it says "not registered on network" ...the sim works fine in other phones.....the IMEI is also fine.
heres what i have tried :
1) change sim card
2) change roms
3) go back to stock GB that phone came with
4)wipes (all)
now i think i messed up something with the ril cause i changed it and i think thats where the problem started.
i got backups of the efs but i dont wana go there unless absolutely sure that the problem is there.
(is there a way to i dont know like check the integrity of tue efs or something)

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I'm having a similar problem with my s2
Sent from my X10i using xda premium

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if someon could plz check this for me.
i went into the service mode menu *#197328640#..then option 2 which is version info ...then option 1 which is SW version....then option 1 which is READ IMEI ...now when i selected that it said IMEI :NOT SUPPORTED
i dont know if thats normal...so if someone could please try this and let me know..i would be extremely thankful

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ok so i did a lil experiment :
i purposely messed up my IMEI to that generic one with lots of zeros ...and suprisingly the calling function is back and i can use the phone normally except ofcourse the fact that the IMEI is messed....
Then i restored to get my own IMEI ...and together with my IMEI ..the problem came back too....
(oh and once again if someone could plz confirm the thing i asked about in previous post thanks)

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My imei says not supported "/
Sent from my X10i using xda premium

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Network signal issues
Have you tried checking network operators and manually searching and selecting the Network provider?
also have you tried flashing a different radio ?
regards