@kerdak ,Kedrak, Try holding the button for 10 sec's or longer to see if powers on, remove SD card and restart the device. If removing the memory card solves the issue, your SD card may be damaged. In this case you need to get a replacement SD card. See below links, fairly good article's that discusses your issue and talk of other reset procedures and software issue's perhaps,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
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UPDATE 02 22 2017
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I had jumped the gun here a bit, if the phone was not already disassembled and repaired of the water damage/corrosion, you should perhaps do it now. Stop charging or powering up your device until the liquid damage is addressed correctly, as you could be shorting out components inside the phone. You really should take care of the corrosion that is happening inside the phone from the water damage as that could be your problem. A partial tear down link for your device Link #4, disassembly guide will enable you to get inside the phone to remove the damage/corrosion caused by the liquid(more disassembly guides and info. by pressing on the picture of your device in upper right corner of page). Use the 5th link as a guide/instruction on how to clean/repair the device from liquid damage. After this you will be able to power on the phone and see if further damage has to be addressed. Good luck.
@kerdak ,Kedrak, Try holding the button for 10 sec's or longer to see if powers on, remove SD card and restart the device. If removing the memory card solves the issue, your SD card may be damaged. In this case you need to get a replacement SD card. See below links, fairly good article's that discusses your issue and talk of other reset procedures and software issue's perhaps,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
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UPDATE 02 22 2017
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I had jumped the gun here a bit, if the phone was not already disassembled and repaired of the water damage/corrosion, you should perhaps do it now. Stop charging or powering up your device until the liquid damage is addressed correctly, as you could be shorting out components inside the phone. You really should take care of the corrosion that is happening inside the phone from the water damage as that could be your problem. A partial tear down link for your device Link #4, disassembly guide will enable you to get inside the phone to remove the damage/corrosion caused by the liquid(more disassembly guides and info. by pressing on the picture of your device in upper right corner of page). Use the 5th link as a guide/instruction on how to clean/repair the device from liquid damage. After this you will be able to power on the phone and see if further damage has to be addressed. Good luck.
@kerdak ,Kedrak, Below is a fairly good article's that discusses your issue,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
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@kerdak ,Kedrak, Try holding the button for 10 sec's or longer to see if powers on, remove SD card and restart the device. If removing the memory card solves the issue, your SD card may be damaged. In this case you need to get a replacement SD card. See below links, fairly good article's that discusses your issue and talk of other reset procedures and software issue's perhaps,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
@kerdak ,Kedrak, Below is a fairly good article that discusses your issue,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
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@kerdak ,Kedrak, Below is a fairly good article's that discusses your issue,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
@kerdak ,Kedrak, Below is a fairly good article that discusses your issue,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
@kerdak ,Kedrak, Below is a fairly good article that discusses your issue,check it out may help. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
http://support.sonymobile.com/global-en/xperiam4aqua/faq/I-cannot-power-on-my-device/