Hi, I have a Galaxi S 6, and since a while ... since they updated the operating system to Android 7.0 I did not recognize the SIM. In the end they told me that it could be that when updating the system, sometimes, the text file where the MEI is lost and deleted (since you were no longer updating the 7.0 update). I took it to an official house in the AQUA Commercial Center, here in Valencia, and it was not possible to install the TXT file (Imei), they tried to make a RECOVERY, SUMMARIZING..... In the end ... it does not load the optional system, it stays the black screen, when you give it to reboot in a safe way to fail-safe, it is shitting and it stays hung and from there it does not come out, always the same. When you stay charging and do not move on ... the battery is used up because it stays on but locked. Could someone help me. Thanks and best regards

reinstall the operating system using the download mode, first remove and replace the battery. volume test - + start button + power button. If it does not enter the download mode, give it volume +, start button and power button, in both cases you have to press and hold the 3 buttons, from there you must reinstall the software and then repair the imei with a samsung original octoplus box (no crack programs) and problem solved. In case you enter the download mode by accident do not turn it off, press the start and power keys at the same time for a while