I have a nextel 7520. I bought a 7100i online. When I insert my sim card into the 7100i, I get a sim card error. This is a company issued 7520. Is there anyway to easily upgrade to a 7100i without getting company approval or some kind of work around? I hate the screen on the 7520, so I want to upgrade to a 7100i. I did a lot of searches here and got very mixed answers.

Wirelessly posted (Cingular 7130c: BlackBerry7130/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

The sim card should be exactly the same. Maybe a problem with the device.

Contact Nextel. The SIM cards may not be exactly the same.
Option - Nextel has a few different SIM cards.

Wirelessly posted (Cingular 7130c: BlackBerry7130/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

Not to argue, but what could be different with their sum cards?

They have several different variations of SIM cards. They have different amounts of memory. We have TONS of Nextel BBs at work and we need to have SIM cards swapped out all the time as people switch devices.

Wirelessly posted (Cingular 7130c: BlackBerry7130/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

We have 32k and 64k cards with Cingular, but any sim will work with any phone. I don't see why Nextel would be any different. It's just strange to me. Any one have more specific info on why they have multiple sim cards?

I guess not too many people have done this. I have tmobile at home and I know its no problem to switch sim cards, but apparently nextel is different. And, blackberry is even more different. I can switch the sim card, but all the data stays with the olf blackberry and doesn't get transferred to the new phone.

Nextel is not GSM. They are iDen. A completely different network with a different SIM card.

Cheapergear

The SIM cards are not identical and will not work 'cross phones. I had to call Sprint/Nextel, ask for a Nextel BB rep then provide PIN on both old and new phone. Once that is done, takes a while for phone to 'acquire' Nextel network.

My 7100i works fine and I don't miss the 7520 unless I am in multiple IM conversations.

We tried that here when the 7100I came out - In fact, my boss got a 7100I and was told to switch the SIM to transition over. It never would work and they ended up sending him a new SIM card.

i bought my 7100i online and just swithced sim cards .... only this happened was i lost my nextel.blackerry e-mail, now i have a sprint.blackberry e-mail and a new pin #

You need a 64k sim card. The 7100 does not run on a 32K sim card like the 7520.

I can confirm this.. as I went through the same issue.. 32k for the 7520 64k for the 7100i.

Put the 64k sim back in the phone and call NexTel... they will do what they have to do to get the phone working...

The phone is much better then then 7520... other then I still cant get MMS working..(and yes I have the data plan, text messaging plan etc.)

All right then. The definitive answer is this. To switch from 7520 to 7100, you must call nextel and get them to make the switch for you.