same problem with me too. i brought my Nokia N900 about an year ago and now i am facing the same communication error. i tried re-flashing but it is of no use it works hardly an hour and again i got the problem, i tried to change sim but not work. i think Nokia is now saving its cost for R&D and selling us phones with full of shitttt...
it looks that same problem is with lot of people that means it is a design faliure of nokia and nokia has to change all of N900 but they only care about money.
so i decided to end up with Nokia, now forever NO to nokia and i will suggest all of my friend for not buying nokia shitttt....:mad :

Hi, I'm new here .
i have the same problem and some unauthorized Nokia repair service told me you have to pay about $50 for RPL Request from Nokia because of no IMEI !
Is this anything to do with the RPL ?

Same errors,sim and gps no longer work i'm sending it in with only 3 weeks left of 1 yr warranty.NOKIA YOU BETTER FIX IT!

So a little update.
I reflashed my device in good hopes with pr 1.3, but still got the error.
Then after reading this thread, just applied a little pressure to the upper right area under the battery where supposedly the gsm modem is situated. After reboot, no more error.
So this is a hardware issue for me atleast. my phones HW type is RX-51.
Tired of carrying my old C6-00 which is a poor substitute for my n900, so I guess, I have to carry around two. 1 for fiddling around and one for calling.

Edit
Tried to reproduce the issue, and I can say that, it happens from regular use, while holding the device in two hands and opening the keyboard, then applying only a little pressure from both sides, can easily make this HW defect reappear and after some more handling disappear again. So a cold solder joint or worn out contacts somewhere. Pity, that I do not have the equipment to attempt to resolder the modem part.

http://talk.maemo.org/showthread.php...73#post1135573

I have already posted in this thread with this problem. My handset was replaced by Nokia for a new one. Now I have the exact same problem with this handset. So goodbye to my amazing N900 (bar the problems) and goodbye to this forum. It's been great, with some very clever and helpful people.

Great news, worked for me, , last whole week i was frustrated and reading many threads and information on this issue. In my case i can say its not at all a hardware problem. It was problem of my laptop with Windows 7 which was not flashing my n900 properly.

Starting form the beginning, one day my phone suddenly started a loop of rebooting. then i tried to reflash the device (not eMMC Image) (i.e. flasher-3.5.exe -F RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin -f). My phone atleast stopped rebooting but i end up with another problem of No Connection to service provider.
I tried to reflash 2-3 times more but same problem, then i realized that i was flashing with windows 7 and the process of reflash was not completing properly (it used to complete in 2-3 seconds don't know how) and since i was not using "-R" in the script my N900 was not restarting on its own. and if I restart it was showing an error "All telephony....". finally I tried from my Office laptop which has windows xp and in the first attampt it showed me "flashed successfully" (not sure about the message after completion of reflash, coz i did not bother about the message that time). and when i booted n900 it started without any error. one more important thing, while flashing i forgot to insert my sim card. so when i tried restarting with sim card, there was no error. I hope my experience would surely help some one. I love my N900 .

This may not be the exact problem, but it may help a few people either way...

I had an issue with my n900 that was solved here regarding my signal dropping intermittently. If you take off the back panel (phone face down), the plastic panel to the left houses the aerial. If you take that off, underneath is two little prongs. You can bend these upwards a little fairly safely and replace the aerial.

In my case, the aerial wasn't secured down properly. Solution for me was to place a small piece of blu-tac underneath the top left corner of the battery cover to ensure extra pressure was being applied to the aerial and the connectors underneath.

Sorry if I've missed the point - I haven't read the whole thread, just the last few posts which talked about pressure being applied, and it was this same pressure that actually fixed the signal issues for me when the signal was dropping intermittently.

Happy Christmas, S

i was also getting same problem.i tried to reflash but it showed cmt flash failed.then i opened device there was dust on the board.cleaned the board.then flashed.it got flashed.and i could see network for an 2hours after same problem started again.
now i have put packing on sim card under battery.it works for some time and its give error again.
staloa where did u put packing can u post pic

Hi Red X,

I can't take a picture as am at work and my N900 is he only camera around, however, I this post will help:

http://talk.maemo.org/showthread.php?t=80339

The GSM Antenna is in red. It is the underneath of that piece of plastic that you can access the pins that I bent up and I placed the packing material right on top of where is says "GSM" in that picture.

Let me know how you get on!