Jiayu S3 hang/reboot after unlock

Hi guys!

I'm noticing some strange behaviour (lately more frequently):
After entering my unlock PIN (pressing the enter button) the phone will hang and finally reboot. Any idea how to get down to the root of the problem?
I can connect to my phone via adb, but I don't know if there are any features commands that I could use to get more information on that.

Looking forward to your input :)

Jiayu F2 touchscreen reverted on half low screen after flashing wrong recovery

As per object.
I've also formatted, restored stock rom and stock recovery but now the touch screen is not responding.
Someone can help me or send me to the right guide? thank you very much.

Andrea

which firmware do you use on jiayu s3

Please let others know :)

Bricked Jiayu S3 Advanced help!

Yesterday i flashed my Jiayu S3 to lolipop (i tought) and i just bricked my phone!
After reboot it was just dead.. when i plug into pc with USB i hear the connect sound and after 2 seconds the disconnect sound. This keeps on going until i pull the USB plug. When i look in DeviceManager i see it refresh after every sound, but nothing pops up (unknown device or whatever). I deletet all usb drivers with usbdeview, restart pc but still no changes.
I tried with or without battery, but without it does nothing at all.. i tried holding Vol+ or - or both or with power button, but nothing.
Read some threads about unbrick and install correct usb driver for jiayu s3, but all the options they came with does not work on my device!
I'm a little despered now and don't know what to do.. i get the feeling that my 2 weeks old phone is dead? :'(

My pc has windows 7
Did the flash with SP Flashtool 5.1516
Did not untick preload in flashtool, i guess i got the wrong preload or something??

Please help!