Hello community ,

I have had my N900 for a while, but starting yesterday, it started having what appears to be GSM connectivity issues. I search around and found a lot of people have the "no sim card" error. However, mine is different: the phone goes from having strong signal and 3g signal to 0 bars, or sometimes, it goes from a strong signal to the red symbol indicating no SIM is inserted. After a few minutes (non consistent amount), the phone usually restores the connection. Restarting works sometimes, but others it turns on with that symbol/no signal for a few minutes. Also I would like to note a few other weird things:

The phone restarts itself (not frequently, but maybe twice a day), and it takes longer than it used to to power up. Also, sometimes it comes up with the message popup about time, timezone, and such. What I have tried:

1- I restored all kernel settings to default settings ( I had it overclocked to 850- Didn't work)
2- Replaced my SIM with a brand new one. ( I have T-mobile).
3- Made SURE my SIM is inserted PERFECTLY!

Some people have suggested putting some sort of paper between the door and the SIM, others suggested to re-flash. However, I dont believe either of those options will help me since my case is different (it only does it sometimes). I would really appreciate it if somebody has an idea of whats going on, or what I could try. Any help is very well appreciated. Thanks again!

Nobody?

I had a similar issue and the only 'fix' was to send my N900 back to Nokia "care".

They replaced it (and even that took them 4 weeks...)

I had an issue with my Voda SIM where it started to only show a 2G signal.

Phoned them up and they sent out a new SIM that now works fine.

Update: This is extremely weird, but I tried changing the battery back to the original one (I was using an extended battery), and so far, it has not failed!!!!!!! Im guessing it might be how much it is pushing on the SIM card slot or something. Can anybody validate this?

Andd... I can reconfirm.. The issue never happened again. So to be sure, i re-replaced the battery with the extended one, and sure enough, the symbol popped up, then I put the OEM one, and hasnt showed up the whole day. Weird! It must be a pressure thing..

Anybody?? Some details, if it will help. The battery is a 2400mAh Mugen battery, and I am more than a 100 percent sure it is causing the problem. Does anybody like a video of what is happening maybe? But heres what I just tried: I taped the SIM in place, put in the extended battery, it took longer than usual to power up, then asked me to confirm the settings (this only comes up when I put in this battery), and then it started going from No Sim symbol, to 3g connectivity, back to No Sim, and sometimes just No signal! I replaced back my original battery, and it hasnt failed since. I have tried this test so many times, so the battery is the problem. And the fact that taping the SIM in place didnt matter, means (to me) that it is not the pressure the battery is putting on the SIM (meaning this is not an external problem, it seems). Any thoughts/suggestions?