After a lot of reading and rereading. Downloaded ODIN this is a loader prog for Samsung phones. Downloaded new Firmware no the correct one but as near as
I could get and unzip. Remember my phone is useless so trial in place. Downloaded Samsung phone USB driver.
Open ODIN, put phone into Download mode (press 3 buttons and wait) Connect phone to laptop with cable. tick Auto reboot and 'F' reset time'
Press AP button find browse for unzipped firmware, open. Wait for it to set com no and show file in AP line. Now Start, progress bar will show how things are
going. When it has finished a readout of how things are is shown in left paine. My phone was not quite finished so I waited about 3 mins.
Bingo phone now not turning off and working fine but......I used a 'close' patch so some hings were in Chinese. It is not Google anymore more Samsung. I have got around these eg choose keyboard type etc. language.
I could re patch another day but this is just excellent loads of Apps if need be After a few hours all good but slightly different.