Nextel I90C with Boost SIM

Hey, I got a problem with my I90C and the SIM. I used to have Boost Pre Paid SIM with Boost Mobile I215 phone. I just got a unlocked Nextel Motorola I90C and put my Boost SIM card in and it worked fine.

I can make a call and I get full service but when I try and save a contact into the phone book and click "done" it says "Check SIM" and then I can't do anything until I power off. When I power it back on it's not saved and it worked before but then it got erased when I took the battery out.

All my contacts work fine with the SIM in the I215 and I thought the SIM was maybe full so I saved and deleted all the contacts and tried it again on the I90C but it still says "check SIM"

Does anyone know what's wrong with it or what I have to do to get it to work? Has that happened to any of you? Thanks guys

Catch me on AIM if you want - Novak921

i have often been told that nextel sims and boost sims are not always compatible. They can often kill the phone over time if its the wrong sim card.

Are you referring to the difference between Falcon and Condor SIM cards? I'm no expert on Nextel stuff but when you said that I remembered sticking a post in this forum about the subject. Thanks to G2gGolfing69 for the info!!!

Difference Between Condor and Falcon (SIMs and Phones)

yeah Im still learning about the condor and falcon things iv'e read a little about them but still reading on but yeah I was just wondering if the phone has physical built in memory that I Can store the contacts on instead of using my sim since it's 64k