DON'T PANIC!! DON'T PULL OUT BY FORCE!! PUT YOUR PHONE DOWN AND READ!!
What happened to me, I have a nanoSIM card, and since Z2 uses microSIM, I had to use an adapter nanoSIM -> microSIM. I took the tray out of the phone, my nanoSIM fell out, and tray went back in the phone with only nanoSIM adapter, without the nanoSIM card!
And then you have a problem, because you cannot pull the SIM tray out of your phone! It gets stuck, so don't pull it out by force! This might also happen with just a microSIM card or adaptor with nanoSIM card and maybe even with only the tray without anything.
Reason is, because there are 3 little pins inside the phone, above the place where microSIM card has contacts, to keep it in place. In my example, because only nanoSIM adapter was inside without the nanoSIM card, that created a hole, in which pins got stuck. So those 3 little pins were blocking the nanoSIM adapter to come out.
Red marked space is the culprit.
I did some quick googling and to my surprise I didn't find anything specific for the Sony Xperia Z2, only some advices for other phones like iPhone, Nexus, HTC... While they gave me some tips and guidelines, Z2 doesn't have a system like other phones with some "eject" button tool so it was a bit different. But I'm happy to announce I did get it out, and I will share my instructions to help others should this happen to you (but I hope it doesn't!).
I'm trying to help you here. This worked for me, but it might not work for you. Everything you do is at your own risk. Read this and adapt to your situation. Don't blame me if something goes wrong!
- Put your phone on the edge of a desk, face down, so that the SIM tray area is only just over the edge. Find a very thin but very sturdy, hard plastic. Something like little plastic packages that hold tiny stuff. Look at the picture what I mean. You can probobly use also something like a very thin screen protector squegee thingy, or something else. It's important that its sturdy, but also thin. I had to use 2 layers, because 1 was too thin. Experiment with this a bit.
- You should cut the plastic "tool" that will help you so that it's width is as the width of the nanoSIM card or preferably slightly less (so you can put it inbetween the hole space).
- Now the actual work: use both hands, Im using one hand just to illustrate what to do, and I didnt stick the adaptor in just to take the picture, thats why only tray is visible. With one hand (finger) gently pull the tray (just a milimeter maybe, just so it starts to go) and bend it down slightly. With other hand, hold your plastic tool, push it inside the phone, above the tray and adaptor, but in the "hole" (marked with red o nprevious pic), on far fright side of the adaptor. Apply pressure up with the tool, wiggle a bit inside-out, and try to apply pressure UP all the time and wiggle, and at the same time with other hand slowly pull out the tray. What you are doing with the tool is pushing pins up, which pushes them out of the hole, which enables you to pull out the tray. It might take some tries, be patient and gentle. If you pull out too much, push slightly back in, and retry. See picture to easier understand what you're supposed to do.
- You should be able to get the tray out. Now never push it in with only adaptor
Thanks for your attention and have a great day