Found these inside a non-working 71B

[Raymond Del Tondo]

Hi Mike,

a small side note: There are several areas of battery acid contamination. On the first pic near the PCB edge and the 6th connection from left, and in the 2nd pic in various places, even at and under the piggy-packed ICs.
So if the unit won't work after resoldering the other wires, this could be another area for cleaning;-)