[Galaxy S II Q&A, Help & Troubleshooting] LosserKlosser:
Okay, so - first off, let me give a quick intro: I am really sorry if I post this in the wrong forum. I AM a noob.

I've been a long time reader (and a very happy user of the great knowlegde base and ROM development here on XDA!) and this is my first post. I'm not anywhere near to be a Linux/Android wizard but on the other hand I have gotten S-off and root on my Wildfire S, have tried different ROMS, link2sd, modified GPS files with root explorer etc. That's kind of my level.

-------

So - now to my question. Please be patient with me, it's hard for me to explain in simple terms and english is not my first language. I WILL get down to facts and numbers.

I've decided to move to a more powerful device and I have just bought a Galaxy S II, bought unlocked from my provider. So basicly all I should have had to do when I got my GS2 in the mail was to pop out the SIM card from my Wildfire S and pop it in the GS2 and it *SHOULD* have been working. Problem is - it works 'kinda'. Yes - it works in the worst way - from time to time. I am puzzled!

I get very bad reception and most times NO reception - no signal.

The SIM card does not get rejected by the phone as if the phone was locked, and if I go outside I CAN get a signal, and I CAN make calls. Sometimes I have been cut off. Now I'm not talking about me not just getting data or GPS signal - I'm talking about 2G GSM signal for just making calls and texting. But outside downtown I HAVE had the H+ sign for data appear and I HAVE downloaded from market with the troubled SIM card.

So one would think that the antenna/modem(?) in the SG2 does not work properly. Well - I got me a pre-paid SIM card from the best covered provider in Denmark. I pop the SIM card in - I get a fine signal. Data and GPS works well, calling and texting - no problem!

I have tried 2 other SIM cards from my provider from friends phones - CBB using the Telenor network - and results are the same. Very poor signal, sometimes no signal.

So here's the facts from inside my appartment in a larger city well covered from several providers in Denmark:

- SIM card from my provider in Wildfire S gives me a signal between -80 and -90 dBm and 10 - 15 asu. All functions work, GPS, 3G data, calls, MMS, texting.

- The same SIM card in the GS2 give me at best around -100 dBm and 5 - 6 asu but often drops to -111 dBm and 1 asu. I have seen -113 dBm. Useless.

- SIM card from another large network provider gives me 80 - 95 dBm and 8 - 15 asu.

- I have checked if the phone is locked - it is *NOT* SIM locked.

Remember - this is all in the same place in the same chair in front of the same table. If my provider had a poor signal Wildfire S should be affected as well.

Can my SIM card from my provider somehow be incompatible with the SG2? I have of course called my provider and explained all of this. They had NO clue why it happened but would mail me a new SIM card before doing repairs.

After a factory reset Wildfire S will pop up and ask me what provider I am using after detecting SIM card (select SIM service prompt). SG2 will do the same thing on the pre-paid SIM card - not on the SIM card from my provider. Does this mean anything to any of you?

Is there a way to determine the type of the SIM card in the phone? I would like to know if the two SIM cards are of different types using different technologies - whatever - so I could determine if the SG2 was not compatible with my providers SIM card.

Model: GT-I9100

Android: 2.3.5

Baseband: I9100XXKI4

Kernel: 2.6.35.7-I9100XWKI8-CL616395 root@DELL149 #2

Build: GINGERBREAD.XWKI8

Country: Denmark

Provider: CBB - using the net of Telenor

If you are still with me this far - thank you very much!