Under the battery the board contain this numbers:
K91 29KEY2
OUT 080311
0843
thats all i can see under the battery anD there is nothing written when i filpover the board only a number 1.77 written on the cord to the display. here are the pics of the circuit nos under the battery i hope the are focused enoughed to view the nos!
edited added the snapshots of the circuit when i flip over!