20 Most Recent AT&T LG CU515 Cell Phone - Black - Page 4 Questions & Answers

Contact your network provider, you'll need them to supply you with a PUK code.

nokia 5310 security code reset

Sometimes you can take the battery out while the phone is still on, wait a few seconds, and then pop it back in (this forces the phone to reset itself). If that doesn't work, take it to your local store.
If it's under a year old, it might still be under warranty and you can call 1-800-801-1101 for warranty replacement.

its in your settings, you can try att.com/wireless and look at your device tutorials of the phone. Should be in sound settings

try wiping off the gold contacts on the sim with a qtip and wiping off the contacts on the phone. Make sure its in correctly. And if its still not working you may need a new sim.

http://www.unlock-free.com/nokia-master/
Takes care of most nokia phones. It's a free solution.Please follow site instructions.
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