Hi Cheeky, and thanks.
Found I could read/write/verify with the Eeprom on the board. As I did it several times with the two different bins for screen options and always got the same outcomes, tend to feel that the chap who suggested that if the backlight cycles, the M/proc is duff might be right. Mind you, have some blanks coming from China to programme.
Noticed a board on Ebay where they don't specify screen, but thought go for it as have the bins.
Gather supplied board is TP-SIS321.PT751 - Chris.