They aren't tight enough if all those terminals with a bolt passing through don't show 0 ohms.
B3 and B6 wire to 7 and 9, so those resistances shouldn't be different. It's unlikely for both of those wires to be loose which is why I asked about the black wires at the headphone jack, as that's a common solder joint that doesn't get enough attention, and it could cause a deviation at both terminals.
