Sony Xperia Z3 - Lollipop - Signal bar disappeared, no SIM would work

I'm experiencing problems with my 2 yo Sony Xperia Z3. Today i've changed the SIM card from polish T-Mobile to Orange (I've been using Orange for alot of time, even this particular SIM, and 1 month ago have unlocked the network to use T-mobile) and now it seems like none of the cards would work. After turning the mobile on there's no SIM pin typebox and the network stays at NO SIGNAL (grey bars with an X on them) What I've tried: - rebooting (changes nothing at all), - different SIM card (still this same happens), - turning plane mode on (would make the signal bar disappear totally after trying to turn it off) Any clues?