There is an 8 point series of pins labelled Button Board with the following configuration left-to-right as I look into the case:

x=pin present o=space(no pin present)
x x x o x x x x
8 7 6 5 4 3 2 1

labelling for each pin is as follows:
1 - labelled as "1"
2 - SLP
3 - HD
4 - no label
5 - KEY (no pin)
6 - PWR
7 - CR2 ?maybe not a pin reference?
8 - BTsolderblob on third character