NH ALCO FA w 5vPS2 Died. Options?

It's real easy if you can get the special 3-volt board designed with plugs to replace a 5-Volt board.  Using the upgrade kit, it would be no different than any other upgrade---gut and replace virtually all wiring.  I'll leave it to others to comment on the complexities introduced by the slave board.

You need the 3V board with the 5V connectors, a 4 ohm speaker to replace the 16 ohm one, and the battery & charging port harness (with 3V battery) for 3V PS/2.  The speaker is probably the hardest to find for some units, my SW1500 doesn't have a properly sized 4 ohm speaker, for instance.

Considering the cost of a PS2-3V kit will be $150 or so...why not wait (patiently) for the PS3 upgrade.  According to earlier threads even though PS3 uses LEDs, some variant of the PS3 kit will support incandescent bulbs as used in PS2.

If you smelled burnt electronics, I'd think you might find the bbq-d component(s).  While it can be difficult or impossible to replace PS2-5V parts because of inaccessibility, why not spend a few minutes and give it a shot- you may get lucky.  If you can't see the culprit, you can usually sniff around the board to narrow the search.

If the Positive voltage purple wire touched the chassis than you had AC on the circuit and a overload situation.  Is it still shorted?

Since there is nothing wrong with your Slave A repairing your lead A with the PS-2 3V allows you to retain your slave unit.  So a single repair to your lead A.  No changes to your trail A.

I have the parts in stock to repair your engine.  My e-mail is in my profile.   G

There's a good chance that the PS/3 upgrade kit with the extra board to support incandescent bulbs will be more expensive than the current kit.  Since for an existing engine you'll get no more functionality, why wait a year or more for the kit to be produced?

Agreed - the TBD cost and TBD availability greatly complicates matters.  But my logic is the PS3 is current technology and PS2-3V is no longer used for new engines.  To your point, I'd say it's PS2-3V that provides "no more functionality" and would be a repair.  And it's not a swap-it-in repair as he has to change the battery, speaker, some wiring, etc.. OTOH, a similar re-work effort using PS3 would (IMO) be an upgrade giving him the "functionality" of current technology (i.e., potentially easier future repair), elimination of the battery, and even LED lighting if he so chooses.  PS2 vs. PS3 functionality has been discussed in other threads. I see that MTH just released an Alco FA in HO so while it may mean absolutely nothing for O, it suggests that MTH must think there's some demand out there for FA's.  Thus, there is a glimmer of hope that they might later provide an upgraded FA soundset for O that would take advantage of the larger PS3 memory.  

Separately, the slave issue is interesting. If the slave uses the 10-pin tether that carries the incandescent lighting signal, then I'd think you'd have to stay with incandescent lighting in the main A unit.

Plus the slave board may have to be changed if it isn't compatible with the PS3 kit and it may be some time after PS3 kits get released before slave kits are available as was the case of PS2.

I'm just not seeing any percentage in waiting for the PS/3 upgrade that has no fixed schedule for a replacement.  One would have to assume that you wouldn't be trying to add functionality to this existing locomotive.  If the board later dies for some reason, you're still faced with replacement, maybe then the PS/3 will be available.

I purchased the 3 Volt replacement kit from GGG.

There is very little room to install it and keep the smoke unit. (Distance from front of smoke unit to rear of front motor is approximately 3 3/8". Board distance between mounting holes is 3 1/2".)

I tried turning the smoke unit on the exhaust axist to gain more room. That doesn't do it and smoke unit is to big to mount crosswise.

Any ideas?

You could either pipe the smoke in or take a look at the MTH HO fan driven smoke unit, it's smaller and fits in amazing places.   I connected one up to the PS/2 board and all seemed well, it smoked pretty good, certainly prototypical for a diesel.

Can any smoke unit be prototypical for an Alco?  Thick & black.

To my knowledge no smoke can be colored black coming out of a toy train smoke stack.  The fluid is of mineral oil giving the whitish color.

Thick, yes, white keep working on that.

Enjoy!!

Black smoke could leave dark stains on walls and lungs, just like a prototype

AFAIK, the 5 volt and 3 volt slave boards are the same board.

MTH part #AC-0000011

 You are correct and the slave is 5 volt.