Depending on which model of the Xperia Z4 Tablet you have, try removing the SIM and or SD cards from the device and start it up as you would normally do with the power button.
Does the device still continue to restart over and over again? If it does, perform a software repair using Xperia Companion as the software will be reinstalled in the device when you do this. Do note that all data stored on the internal storage will be deleted when you perform this process.
Hello and thanks for your suggestions. I have made all the mentioned options and my sony Xperia Z4 tablet continues with the infinite restart, I could not solve the inconvenience. I would appreciate if there is another alternative. Thank you Ricardo Pedraza Trujillo
If it continues to restart even after a software repair has been completed, there is something wrong with the hardware in the device and you will need to get in touch with the Local support team in your market.
They will assist you further with arranging a repair for you and answer any questions you may have regarding the repair.