Looking for good used PS2 Steam boards for a PRR Decapod MTH # 30-1176-1

Rob,

I believe that the PS2 3 volt boards are pin compatible with the 5 volt boards and will be able to use the existing wiring harnesses (excepting the battery lead of course).

Unfortunately, that's not exactly the case. The 3 volt and 5 volt PS2 boards have different physical headers, although the pinouts are the same for both board types.

You have 3 options:

• Obtain a PS32 board with 5 volt headers from MTH (these boards are available with either type of header). Although it's a slightly different form factor and is also just a bit larger, it will have the exact same headers as does the PS2 5 volt board.
• Remove the headers from a defective 5 volt board and from a new 3 volt PS2 board, and swap them.
• Use a 3 volt PS2 board and replace the existing 5 volt wiring harness with a 3 volt wiring harness.

In the first case you'd discard the battery. In the other 2 cases you'd swap the 8.4 volt battery for a 2.4 volt battery (or, alternatively, for a BCR or super capacitor). In all cases you'd swap the existing 16 ohm speaker for a 4 ohm speaker.

Over all, the first option is, in my opinion, the best one.