Expensive to upgrade when it can be repaired. PS-2 3V is a good board. Your slave board can be repaired, I do that. If you want PS-3 then both have to be upgraded. The PS-3 diesel does not work with a PS-2 slave. So both units upgraded.
A PS-32 stacker can upgrade the Lead A, but why? It does work with Slave board.
If your PS-2 3V board is bad, that may be repairable too. E-mail in profile. G