Display Layout (from behind, left to right) A12345 B12345 C12345 D12345 E12345 F12345 (Z123) G12345 Connection Blocks (mapping) B1 F1 A2 G2 | E3 B4 F4 A5 A1 G1 D1 F2 | F3 A4 E4 B5 Z3 C1 E1 E2 | G3 D3 D4 C5 Z2 Z1 B2 D2 | C3 C4 E5 G5 Z1 Z1 C2 A3 | B3 G4 D5 F5
I traced the connection block pins to the corresponding display dots. There are 3 traces which interact with the reed switch, these are to the far left when looking at the back of the display, which I've labeled as "Z".
Directly applying voltage to a single dot with a standard 5 volt USB power source, a single dot can flip. Reversing the polarity will cause the dot to flip back to the other state.