SIM Card Error

[BillHuang]

Hello, guys. Sorry to bother you, but my Nokia Lumia 1520 has been acting up lately. My phone tells me that there is a "SIM Card Error" and claims that the card is either missing or invalid. I subsequently changed SIM cards, but the message remained. I even hooked up the same SIM card to a different phone, which functioned, indicating that the problem lies with the phone itself. I even did a factory reset, but to no avail.

Has anyone else experienced similar issues, and if so, how did you go about solving it?

 

[GabrielStorm]

take the SIM out of the 1520. lightly blow on the slot.
reinsert the SIM and see what happens.

also, try using a pencil eraser and LIGHTLY rub
the contacts of the sim card. reinsert the SIM.

it is also possible that the SIM is just a bit thinner than normal
this could cause the issue you are having.