I traded phones with a friend and wound up with this. It had a little problem where the camera did not work. He told me he messed with the software of the phone and that's when it stopped working. So i downloaded a few versions and went to try things.
I first rooted the phone and made a backup of the current software, as i know that this particular model is software unlockable, and you lose the unlock if you do a factory reset or change the ROM. Then i proceeded to trying out stuff.
At some point i came across a firmware which made two sets of signal bars show up, and complained there was no SIM card in slot 2. Obviously, there was only one SIM slot on the back. Hmm. So I opened up the phone to find a footprint for a second SIM slot, measured it with my multimeter and it turns out it was actually wired.
I found a suitable donor, soldered the 2nd SIM slot on, and cut out an opening for it. I actually cut a bit too much, but a little hot glue fixed the issue and ensures i don't slide in the 2nd SIM card too far.
I assembled the phone back together and tested. And... yep, it works. Two SIM cards, two different networks, no problem.
I first rooted the phone and made a backup of the current software, as i know that this particular model is software unlockable, and you lose the unlock if you do a factory reset or change the ROM. Then i proceeded to trying out stuff.
At some point i came across a firmware which made two sets of signal bars show up, and complained there was no SIM card in slot 2. Obviously, there was only one SIM slot on the back. Hmm. So I opened up the phone to find a footprint for a second SIM slot, measured it with my multimeter and it turns out it was actually wired.
I found a suitable donor, soldered the 2nd SIM slot on, and cut out an opening for it. I actually cut a bit too much, but a little hot glue fixed the issue and ensures i don't slide in the 2nd SIM card too far.
I assembled the phone back together and tested. And... yep, it works. Two SIM cards, two different networks, no problem.

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