Invalid Sim Error.. On AT&T.. Tried everything?

[svfusion]

I bought this Lumia 900 from Craigslist listed as "working".. When I put my sim card in, I get the infamous Sim Error.. I do not even have the option to put in an unlock code..


Things I have tried,
Reset the phone,
Flash the Firmware using Nokia Care Suite
Tried using ##782# to get the unlock prompt up.. I even bought an unlock code just for fun.. but I can't even get the unlock option to come up.. What is really odd, ##782# would bring up the normal message.. now after I flashed the firmware, it doesn't do anything..?

My simcard works fine in my S4.. Any ideas?

 

[Muessig]

It sounds a bit stupid, but have you tried another alternative sim card in the device? Honestly it sounds like you've done pretty much everything you can to get it working... could you contact Nokia support?

 

[svfusion]

I have..

Makes no sense to me either.. I have called AT&T, they said the IMEI is good. I guess I could call Nokia Support.. but the phone isn't under warranty but it may be worth a shot.

 

[Doohickie]

Try putting a piece of tape on the backside of the SIM card; maybe it's not making good contact.

 

[svfusion]

Thanks for that.. Tried that and still same thing.. I guess there is no hope for it lol