How do I recover/access Z3C phone memory files after sudden death?

My Xperia Z3 compact got suddenly death from not any specific event, I meant It was during normal use.

I have read solutions and tried PC companion repair, charger for long, charger for short, many push and hold of the buttons (power, volume up, volume down and combinations), the yellow button under nano SIM, magnetic charger, and even I disassembled handset to disconnect the battery and assembly again with not successful attempts to make it alive again ... not any single response, neither display, nor vibration ever,not led indications and not device detected under PC USB link.

Lately it has given not longer 3 seconds periods of display, led vibration but it got long death again. I am keeping on trying but it seems hopeless, so at least I want to know if there is a way to access phone memory to recover some important information

Any suggestion? that would be my way out of this annoying issue., Priority if I get the way to recover files from phone memory, because I know that after flashing it everything will be lost. By the way is there any PC flashing or repairing tool, without phone link detection?

If you know, please let me know, I happened to like this Z3 compact a lot and don't want to be disappointed. teleduardo11@netscape.net