No network or sim is not ready - Galaxy S II Q&A, Help & Troubleshooting

Hi guys I got a big problem, hope u can help.
I have this phone for a couple month already, when I was still running stock I discovered my cell phone would tell me I got no signal. Turning on air plane mode and then turning it off didn't help to get back signal. So I had to turn off the phone and turn it back on to get back my signal. Problem is I never know when it happens until my wife asks me y my cell phone is switched off. So I went ahead rooting it and I flashed a rom on it. But problem isn't gone. I still lose signal but on this rom it shows me full bars, only cannot make phone calls,SMS,and gprs. Tells me no network or no sim card is inserted. I always have to turn off and turn it back on. Now that it is rooted with whatever firmware I can't bring it to Samsung store to fix
please any suggestions?
Sent from my GT-I9100 using XDA App

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Maybe you could try another sim card. Just a thought
Sent from my GT-I9100 using xda premium

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Happened to me just like u describe it , i flashed many Basebands and i found that XXKI4 modem solved my problem maybe you should try too
Sent from my GT-I9100 using xda premium

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Sounds more like a carrier problem. I'd ring them. Check your APN settings too.

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Hi,
I have similar issues. Doesn't matter where I am and how good the network coverage is on all other phones around, my SGS2 keeps changing the coverage icon, from 1 to 4 "sticks" of indicator, or to no coverage state (crossed circle icon).
Sometimes the wireless is not working also, or juts gets very weak signal, though the signal is good on other devices near by.
When I try to turn data network (by pressing the power button and selecting data network activated from the pop up) sometimes it's not even showing the data network icon in the system bar (top of the screen), it's like being disabled data network or something.
I can answer a call and stay on conversation for no longer than a minute, then the signal goes dead and the phone just freezes, when I try to tap red button to end the call - no reaction, I have to turn the phone off.
When I try to make a call it just says "dialling" for ages with no result and eventually the phone freezes, so I have to turn it off and back on again.
Sometimes it turns off itself though the battery was showing almost full icon.
I went to O2 store, they gave me new SIM card, but it didn't help, so it's not a SIM issue.
I did a full (hard) reset - no help.
The guy from the O2 store told me, that I can root my phone, and I will not loose the warranty (I purchased the phone only one month ago), only thing I need to do is to revert it back to original state before bringing it (in case of hardware replacement).
But if it is not a software issue at all, so what's the point of rooting and having all the hustle, then reverting, etc... Can there be some hardware issues? I don't know: antenna, RAM, CPU, whatever???
I hope I've explained everything clearly enough. Any ideas would be appreciated. Thanks in advance.

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What firmware are you on have you tried to Upgrade via KIES .
Rooting will void warranty and will also increase the custom rom counter from zero . Yes they can be reset in most cases .
Rooting will not fix anything at all .
Network is first check are you getting problems at all locations .
When in the O2 store did they check the signal ???
Choice return to service centre
Flash a stock Samsung firmware via XDA possible to also try a different modem via XDA .
None of these will fix hardware problem .
Personally i would factory reset the phone and check all the network details are correct on the phone then return to service .
jje

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burimii said:
Happened to me just like u describe it , i flashed many Basebands and i found that XXKI4 modem solved my problem maybe you should try too
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
Gonna give this a shot ty
Sent from my GT-I9100 using XDA App

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when you have this problem check if you have an imei (*#06#) if the response is empty then you have to reflash...

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Hi all again,
after posting my previous post I phoned my friend during a lunch break at work. We had a quite long conversation and the quality was perfect. Then on my way home I turned on data network and enabled GPS (LOL), then launched navigation app and it took me home without any bugs (I know my way home though I did it only for phone testing).
Now back home, sitting in my room and my SGS2 starts to fool around again: unable to turn on data network, poor wireless signal (but it's good on my PC), the network coverage icon turns into "no signal" state and comes back to normal again all by itself.
I will definitely test my phone again tomorrow on my way to work and in the office. But it seems like there's something wrong with the place that I live. I've moved in recently and must admit, that all my problems with the phone started only then. And I didn't noticed any bugs while at work or anywhere down town.
Meanwhile is there any way to scan/check the area around my flat? Maybe there's something wrong with the in house router, or maybe to many routers in surrounding flats, or some other equipment/hardware things messing up, or just a mysterious house blocking O2 network and hacking the phone LOL??
The only strange thing is that I'm having not just a network/coverage/wireless issues, but the phone freezes, battery full-empty-full-empty status randomly, etc...
BTW, my details:
Model: GT-I9100 (not a I9100G)
PDA: XWKJ1
PHONE: XXKI4
CSC: O2UKJ1
Android version: 2.3.5
Updated via KIES about a month ago, was working good until now. KIES says that at the moment I have the latest firmware.

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burimii said:
Happened to me just like u describe it , i flashed many Basebands and i found that XXKI4 modem solved my problem maybe you should try too
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
Lol I was just about to download modem xxki4 when i found out i was running checkrom(ROM) wish XXKI4 modem(baseband) haha
ya so im running this modem already with the above problems so this isnt a solution
any more suggestions pls?

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rothariger said:
when you have this problem check if you have an imei (*#06#) if the response is empty then you have to reflash...
Click to expand...
Click to collapse
I did that and got a response so I guess I don't need to reflash thx
Sent from my GT-I9100 using XDA App

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therealnoob said:
I did that and got a response so I guess I don't need to reflash thx
Sent from my GT-I9100 using XDA App
Click to expand...
Click to collapse
Its a question of has it the original IMEI .
jje

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burimii said:
Happened to me just like u describe it , i flashed many Basebands and i found that XXKI4 modem solved my problem maybe you should try too
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
Alright I tried ki4 same problem, ki1 and some other I don't remember with the same problem and am rite now on ke7 for a week with no signal lost so far wohoo, and am on checkrom. 4 BTW so switching modems so easy, got its own kitchen application
just for info I'm in China using China mobile
Sent from my GT-I9100 using XDA App

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therealnoob said:
Alright I tried ki4 same problem, ki1 and some other I don't remember with the same problem and am rite now on ke7 for a week with no signal lost so far wohoo, and am on checkrom. 4 BTW so switching modems so easy, got its own kitchen application
just for info I'm in China using China mobile
Sent from my GT-I9100 using XDA App
Click to expand...
Click to collapse
false enthusiasm....
let me list the modems ive tried so far
xxki4, nefk2,xxki3,nekd5,xxki1,xxke7,xxkg3(on this one right now since morning),xxkh3 and xxkl1
6 more modems on the list havent tried, wish me GL