Re: N900 Problem: SIM Card Not Recognized
 

okay....after more than a month of research i came to the conclusion that n900 has a problem with the sim card slot. initial it starts as a hardware problem(sim card slot) and than it goes to be a soft error.
all this is because the sim card is moving...or the connections under the slot are bad, when the phone is on.this will trigger the soft error.
if this keeps happening, the error will not allow the recognition of the sim.
when my phone start having the problem, a reboot would fix it.
after a while it was harder and harder to recognize the sim.
eventually it was not recognizing the sim at all.
i got a different phone,but i didn't gave up on n900.
i took the board out, and with a heat gun, i heated around the sim slot, i erase the hole memory, and format it.
after that i had the pleasant surprise of my n900 recognizing the sim, after i month of no sim.
i try to create the problem back, so i can convince that is the slot the problem, and i put the n900 on a table and start pounding the table to create hard vibrations....and then boom...the n900 lost connection, and after i stopped , it came back.
so the problem it is still there with the slot.not as badly
i did put some rubber between the battery and the sim slot ,so it holds it in place good, even in case of hard vibrations.
this is week 2 after i fix my phone, and it performs good

Re: N900 Problem: SIM Card Not Recognized
 

Hi All,

My N900 started to have the same issue, when I pressed in the middle of the bottom side of the screen bezel when the keyboard was open, it would recognize the sim card so i knew it was hardware related.

I then tried this:
"i did put some rubber between the battery and the sim slot ,so it holds it in place good,"

This seems to be working fine, thanks!!!
Too bad the simcard reader is badly soldered or something, my phone is now about 1 year and 10 months old but I planned to be using it a lot longer. :) Thanks for the suggestion doarmihai!

Re: N900 Problem: SIM Card Not Recognized
 

thanx very much dormehai that works solve my problem. put some papers under the battery and fow top of the battery not a problem at all anymore.

Re: N900 Problem: SIM Card Not Recognized
 

Well. If you are lucky then you may get your phone back. I got an E7 in return... "Sorry we could not repair your N900..."

Re: N900 Problem: SIM Card Not Recognized
 

No sim card is recognizing on my N900. Please, Who can help me out immediately. Thanks in advance.

Re: N900 Problem: SIM Card Not Recognized
 

N900 Problem: hard to start

Re: N900 Problem: SIM Card Not Recognized
 

i have a problem tooo... i ve flashed for all firm disponible... and ;;...doest wrk...mabe se the network mabe not...

Re: N900 Problem: SIM Card Not Recognized
 

n900 conected on pc does t have a problem...mabe out the cable doest recognized...very crazy telephoun :eek:

Re: N900 Problem: SIM Card Not Recognized
 

After reading the whole thread about "SIM Card Not Recognized", I wasn't keen on changing provider with a new SIM.
Last friday, I received the new SIM and checked the card slot thoroughly.
It looked very solid and the SIM is like embedded, and anchored, so no hardware problems. :)
After testing and using my N900 for 2 days, no problems at all:D, just used the sync time now widget and that's it.
Here's my post on the MV thread.

Re: N900 Problem: SIM Card Not Recognized
 

Hello guys...! I bought from my friend an Nokia n900 and until now it worked properly. But 4 days ago it started not recognizing my Sim card.

I flashed my nokia n900, and now it is working, but sometimes when I try to make a call, i see the SimCard icon with the red slash and I am forced to reboot my phone.

I read the posts about this problem, and as I see, my problem is going to be bigger and bigger :( . And I read your post "doarmihai" and I wanted to ask you, did it still works (if you have it, of course)? Did your method worked? Did you hold the heat gun near the board or far from the board?

Re: N900 Problem: SIM Card Not Recognized
 

hi freind;s i;m facing the same problem !! i use n900 and is working fine more then 2 mounth now the signal is going and coming i did put some papaer and every thing is working for some times and the signal is gone and the sim card logo with the red line appers
i try to update the phone still the same problem !! an body know the sorce ? if is a electrical problem tell me where to look is is software can you explain how to fix it !! thank you

Re: N900 Problem: SIM Card Not Recognized
 

same here i start testing the paper solution and give it a try looks like nokia buildt in a self destruction module into n900 ;-)

Re: N900 Problem: SIM Card Not Recognized
 

so far so good the paper solution works fine no more sim card trouble

Re: N900 Problem: SIM Card Not Recognized
 

N900 is very sensitive when it comes to SIM. try a new SIM card, IT WORKED FOR ME. old SIM works on other phones but on N900 it does NOT.

Re: N900 Problem: SIM Card Not Recognized
 

I've had this error three or four times over the two years that I've had my N900, and on all occasions, it's been fixed without changing either the phone or the SIM.

For me, the problem happens when I'm trying to do too much in the way of overclocking / undervolting. I didn't make the connection the first time and reflashed the whole phone. Some months later, it happened again whilst I was playing with higher CPU speeds; I went back to slightly more conservative settings (250-900) and the problem went away.

Recently (many months after the above, same hardware), I started playing with 250-1100, with SmartReflex on VDD2 only... it seemed stable. But, a few hours of that, and some use of the memory card, the SIM dropped out. I reverted to my previous settings, and it reverted to working flawlessly.

I haven't isolated the problem further yet; perhaps I could sustain 1100MHz with more voltage and no SmartReflex, but I'm not sure that I intend to try. The observed evidence from two years with the same device is that my particular N900 is happy and stable at 250-900 with SmartReflex on VDD1 and VDD2, and that pushing it further than that works for a few hours, but is not stable.

Your mileage may vary; some people will have a loose or malunctioning SIM card, an unlucky few will have a broken phone, but I've reproduced the problem enough to be fairly sure that in my case, this is the cause.

Re: N900 Problem: SIM Card Not Recognized
 

I faced similar issue after reflashing. But i re flashed with firmware file from some other region . To be specific I'm from India instead of installing region specific firmware [http://tablets-dev.nokia.com/nokia_N900.php Firmware Download] i installed global firmware. So after reflashing sim is not detected again reflashing with region specific firmware fixed the issue. Hope it helps to some one. :-)

Re: N900 Problem: SIM Card Not Recognized
 

i'm 99% sure this is motherboard problem,
1. try different firmware - was ok for several weeks
2. paper solution another several
3 no other solutions :mad:
i sent my n900 to nokia. i still have warranty on it. this is repair report....
Repair Description
- VID
- Screening
- Replacement- BATTERY COVER ASSY
- Replacement- A-COVER FRAMING
- Replacement- LCD AM 800x480 LTPS CO Caucasus
- Replacement- SCREW M1.4x2.8 BLACK CAMERA-CROSS 360 SP
- Replacement- SLIDE FLEX ASSY (I0101 - I0102)
- Replacement- TOUCH WINDOW ASSY (I0003 - I0005)
- Replacement- A-COVER ASSY
- Unit exchange
- Adjustment
- Software update



History of Job
05-10-2012 - 13:00 - Packed ready to be sent
05-10-2012 - 10:39 - Repair completed
05-10-2012 - 10:12 - Final Inspection awaited
05-10-2012 - 08:27 - Full test awaited
01-10-2012 - 14:37 Awaiting quality control validation
01-10-2012 - 14:31 Received back from higher level repair
19-09-2012 - 06:35 Sent for higher level repair
18-09-2012 - 10:07 Escalation to higher level repair awaited
18-09-2012 - 09:31 Awaiting Inspection
18-09-2012 - 08:02 Repair in progress with technician
14-09-2012 - 10:02 Software upgrade awaited
14-09-2012 - 09:06 Repair in progress with technician
14-09-2012 - 09:06 Repair started
12-09-2012 - 03:59 Screening awaited
09-09-2012 - 15:30 Receipt awaited
08-09-2012 - 10:15 Repair booked

Re: N900 Problem: SIM Card Not Recognized
 

After few months my N900 still have the same sim problem.

I tried a lot of things, but it still in problem.

1) I tried to clean the connectors.
2) I changed the sim card.
3) I tried the "hammer and nail" way. It's was functionnal for few weeks, but now it's still broken.
4) I tried to format it. Same thing

Now I'm very sad. I've this phone since 4 years and I love it, but I think it's the end.

Thanks to everybody who's trying too help.

Re: N900 Problem: SIM Card Not Recognized
 

http://talk.maemo.org/showpost.php?p...1&postcount=18

This works to get Sim 'online' again

Re: N900 Problem: SIM Card Not Recognized
 

Hi all,
I have the same issue with my beloved N900. I manage to keep it running with a thick piece of paper between the SIM and the battery. but the whole thing seems to be a bit sensitive. If the phone case is squeezed a bit, e.g. while being in the pocket, it loses the SIM card connection, and without any warning. Very annoying.

My phone is still under warranty, so I could send it in to Nokia, but I've read that usually they cannot repair this (motherboard exchange necessary), so they scrap it and provide a replacement, usually a N7 or N8. Bad deal!

Has anybody tried out the above solution? I feel unconfortable doing it.

Cheers

Yes i did. And that worked for me. :)

Re: N900 Problem: SIM Card Not Recognized
 

Hi saponga,
What did you use as springs? Was it difficult to open?

Re: N900 Problem: SIM Card Not Recognized
 

I've disassambled it many many times...it's not difficult at all.
Just be gentle and use THIS as guide. FIX IT

Re: N900 Problem: SIM Card Not Recognized
 

I've used a pen's spring,glue and a small screwdriver to remove the cover of the GSM module. You have to do it using the screwdriver as a lever and slowly (part by part) pushing off the cover. It's easy but something scary. That cover is put in place by pressure and actually it might be a little deformed after you got the work done. I can send you a picture if you want but it is pretty similar to those ones from the link few posts ago. But remember, the device is yours the risk is yours.
Good luck ! :)

Re: N900 Problem: SIM Card Not Recognized
 

Thanks for the quick reply. Yes, I would appreciate if you could send me some pictures or upload them here.

What are the springs actually good for? Do they provide some sort of grounding? Or is it a mechanical issue of pressing the ICs down? I apologize for my ignorance.

Now, my SIM card connection is lost while I type on the HW keyboard, i.e. applying some force on the HW underneath the keyboard. When I stop typing, the SIM comes back after a few seconds, sometimes asking for the PIN again. Has anyone experienced this too?

Re: N900 Problem: SIM Card Not Recognized
 

Just mechanical pressure. Actually, AFAIK you might use everything that increase the pressure there... I've got some pictures but i cannot attach it here because the file is big. I've used that kind of pen that has a push button to expose or hide the tip.
Just follow this tips...
And this is EXACTLLY what i did !
BTW, thanks again ForeverYoung and Jabawok !!! :D

Re: N900 Problem: SIM Card Not Recognized
 

Thanks for sharing your experience and the picture. Now I know that not all hope is lost for the best of all smartphones. I will try the repair on the weekend and let you know if I was successful.

I could get a new N8 or N7 in exchnage, since I still got warranty. But I don't want either of them. The only device that I would readily accept in exchange of the N900 is the N9. But Nokia is not selling those in Germany.

By the way, I love the community here!

Re: N900 Problem: SIM Card Not Recognized
 

I performed the repair following your instructions. The issue didn't go away completely, but it is much less severe now. I still need to put a thick piece of paper between the battery and the inside wall, which is then applying additional force on the GSM Module, but then the connection seems rock solid. No more disconnecting so far. Thanks again!

Re: N900 Problem: SIM Card Not Recognized
 

Thick piece of paper worked for me.

I can actually feel the detachment if I use my finger to put pressure on the SIM once it's locked in.