Conrail SD 70ace Heritage smoke and cab light

Sounds like smoke element is shorted to smoke unit housing.  Common occurrence.  You can open it up and make sure it doesn't touch housing.  G

The smoke unit sounds like the smoke regulator shorted and killed the smoke resistor, now you're getting basically a direct short across the track voltage.

For the cab light issue, have you reset the ID, that performs a factory reset on the engine.  Sometimes the lighting is wonky and a reset brings it back.

The speaker hum may be the RS power supply, or possibly the RS audio.  The RS power supply is the generic board that's been used since RailSounds 4, so you could swap one from another TMCC or early Legacy and see if that helps.

Many thanks- new to the hobby (was always an N scale guy), and now new to fixing them... 

Not to be a pain, but any tips on how to fix the smoke unit and how to do the factory reset? I don't recall seeing the reset in my manual- pardon if it is... 

thanks again, much appreciated! 

Well, I'd check the smoke resistor in the smoke unit as GGG says, but I'd think that would take out the regulator triac pretty quickly if it was a dead short.  Tripping the breaker requires a lot of power to be dissipated.

The reset is simply setting the ID again for this engine, pick a new number and then set it back to the original, see if that changes anything.  The reset is in the manual.

It doesn't, I had a engine like that, and Mike Regan told me to go right to the smoke unit not the ACREG.

A shorted ACREG would just provide full voltage to the smoke element. Even if 6ohm element that is 3 amps.

When ever a short is tripping a high current transformer, it almost always is AC center rail to Outside rail short.  G

Thanks a lot! The smoke unit is plug and play on that correct? Is the rail sounds card the same? Will try and open it up later this week, and get some parts. 

Before I started replacing parts, I would pull the RS boards and reseat them.  Some time contact corrosion causes issues.  Make sure speaker is mounted firmly and no items stuck to the magnet like screws or track nails, etc...

Do an engine reset following the instructions with the manual.

Check the smoke unit as mentioned.  G