sim card

So back in June, my samsung galaxy s4 stopped reading my sim card. I tried replacing it multiple times but it just won't work. my phone is essentially a miniature tablet. I can only use it when connected to wifi and for calls and text messages I have a cheap samsung flip phone. does anyone have any ideas on what I can do to fix this. It's not a big deal because I'm replacing it with the note 4 in a couple week; but I would still like to use it until the note is released.
p.s. I have already tried a factory reset.

— modified on Sep 25, 2014, 9:32:31 AM

I think the problem is with the newer sim cards. I put an old card in and even though it's not an active sim any more, the phone still recognized it as a sim card.

I'm sorry to say, it didn't work. But like I said, it's not a big deal, I'll have the note 4 in a couple week. Thanks for your help though.

— modified on Sep 27, 2014, 7:10:37 AM

so today, my s4 suddenly started working. I don't know why or how but it did. I guess it just doesn't want to be replaced lol