Help identifying QSI pre-PS1 Boards

They separated the QSI DCRU lower board.

The horn board is the upper attached to the speaker. It just unplugs. the entire lower and the wiring going to the second board is all one board, just physically separated for the space.

So again, board 1 unplugs- that simple. Then wire your new sound board directly to track power.

Ahhhhhh...now that makes sense! It is 2 boards...

Thank you!

Got it off.  Last questions out of curiosity......

-Would a PS1 board have plugged into the expanded pins where the sound board was or would that require a whole new DCRU that works for PS1?

-I assume this is where the "accepts plugin protosounds" would have gone.  What was the pre-PS1 board called?

@Dd289 posted:

Got it off.  Last questions out of curiosity......

-Would a PS1 board have plugged into the expanded pins where the sound board was or would that require a whole new DCRU that works for PS1?

-I assume this is where the "accepts plugin protosounds" would have gone.  What was the pre-PS1 board called?

Requires the PS1 style DCRU. That plain one is missing key voltage regulators- the battery connector required for PS1.

https://ogrforum.com/...om-board-vs-qsi-dcru

FWIW, just before Christmas, a local customer brought in a collection of MTH engines for inspection and servicing before he was going to turn them over to family. That was the first and only time (started this hobby Dec 2017) ever I saw the pre-PS1 QSI 3 board stack, and because it was still QSI, the instructions for settings is very different than PS1- example resets and so forth.

Again, I can say I have touched a 3 board stack QSI, ran it for a bit, and gave back to the customer (serviced it, new traction tires, lube, and smoke unit re-wick).

Finding those QSI parts- might require someone with a larger parts stash than I have.

Thanks for the information!

I think sometimes I forget how long ago the 90s were...

Board (3) has the (4) diodes, parts for the bridge rectifier, (changes AC to DC).  The large capacitors, Board (1) could, (also) be part of the AC/DC conversion. Horn circuits, and electro-coupler circuits, could also have capacitors.   Capacitors tended to help eliminate a lot of model train chatter, generated by arc, and spark, at the rails. IMO, Mike CT. 

Edit Add:  QSI still in the model train business, there is a website. 

The early GG-1 was like the lionel version and small.  The board would not fit so they cut it and linked the motor drive section by wires.  G