How to re-lock a Windows Phone 8 device (Lumia 920)?

[matthew_b06]

So I have a fault Lumia 920 and need to send it back to Rogers, but I have it unlocked to use on Bell. How do I lock my phone again to Rogers? Does unlocking it Bell void the warranty and they won't replace it because it's faulty?

Thanks.

 

[ImmortalWarrior]

Flashing a locked ROM will lock it again but the IMEI will not match up. Flashing voids the warranty, unlocking does not.

At the worst, you will have to unlock the replacement. If you bought the unlock from Rogers for 50 bucks and the phone gets replaced due to defect, convince Rogers to give you the unlock code for the new one for free. You shouldn't have to pay for an unlock twice because they sold you a defective phone.