Help with SD 70ACe.....sick!!!

Your engine is an early Legacy locomotive with an R4LC, Railsounds power board and Railsounds audio board all sharing one motherboard.  The SD-70 body is not any wider than the afore mentioned boards.  Very tight fit and common to move the boards when installing the body.  It is always a good idea to spread the body at the bottom when putting it back on the locomotive. 

Back to what you have going on.  Can you pull the body again and pull and reseat the afore mentioned three modular boards?  Your Railsounds power board could be bad, or bad volume pot.  Lets deal with your sound first.  Follow the three wires from the volume pot towards the motherboard.  These three will be joined by two more that are from the speaker.  All five wires go into a 5 wire Leoco plug that goes on the motherboard.  Pull and reinstall this plug and let us know what is going on then.  With the R4LC reseated let us know if the engine operates alright.

I have run into bad power boards in those engines ( I have 3) and bad volume pot.  If your sounds are still bad, try another power board from another engine.  TMCC and Legacy power board will interchange.  If sound is still crappy, go to your Railsounds audio board and touch with a wire pins 16 and 18 on the board. These are from your volume pot.   Do this test with the R4LC board pulled off the motherboard.  .

Not to bore you but can you take your continuity meter and put one end on pin 23 on the R4LC board and the other end on the antenna.  You should have continuity. 

Thanks Marty for the reply:

Just to be sure.....you are saying join(touch) pins 16 and 18 with a wire.....I am assuming these pins are for the pot, and by shorting across I am removing the pot from the circuit. In doing this if the pot is bad.......I will have sound????

Tim

Tim, you can do this at the pot also.  You will be bypassing the pot.  Be sure to pull the R4LC board.  If sounds come alive as they should be, bad pot. 

OK tried bypassing the pot and it made no difference. Reassembled after checking all connections and reseating all boards......now have lights forward and reverse...front and rear couplers are working.....but no sound and no motion forward or backwards. I will switch out the R4LC board from another engine tonight and post results.

Curious the lights and couplers work......do they power from the main board??

Thanks for all the help....problem is it a 2 day drive to the nearest service center, so I'll poke around a little more before admitting defeat.

Tim

Is the sound switch on RS setting?  Have you tried to reset the R4LC? IS the speaker connector in place?  G

Go for the Railsounds power board.  Before you do that, pull the R4LC and power the track.  If no sound, do the board.