I really don't know how It happen, one day it started to give me an error after that it stopped working.
I think most of this model N900 users will face the same problem because until now i saw many people are complaining about the same issue
Hope yours will be stable and i don't think that its because of installing some applications or another OS in it.
The nokia N900 hardware might be weak and cant stand forever
Because the problem can initially be delayed by putting pressure on the sim card slot I have a feeling it's a broken/loose connection on the mother board. There may be a hardware fix similar to the usb connector issues, but no one with sufficient soldering expertise has taken a good look at it as of yet.
On the other hand, I still use it as a wifi internet tablet while my telephony usage is through a simple candy bar phone that doesn't do much more than voice, sms and very limited email.
am using my phone as yours only for WiFi connectivity
unfortunately no one from nokia support tried to fix it i don't know why, i think its something with the EEPROM because also the IMEI disappeared from the software means that something got wrong with it.
if you tried to flash the phone with COMBINED it will give failure at CMT means something wrong happens to the EEPROM.
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
