Help! Athearn SD70 ACe is shorting out somewhere!!

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wongsing

Member
Hey everyone, my brand new Athearn SD70 ACe is acting strange. I just ran it on my DC track a few days ago and it was just fine. Today, I took it to Caboose Hobbies in Denver to get the horn sound changed, some momentum programmed in, and the sound turned up. As soon as it was on the test track there it was acting like the wheels were dirty or something (i.e: hunting, resetting the sound, making the lights flash, etc.). The guy there had asked me if the wheels had needed to be cleaned, but this engine is brand new and the wheels looked fine to me. When I got home, the sound was much louder, the horn sound was more correct, and the engine is acting like it has some momentum programmed in. However, when I placed the engine on the track, the startup alarm plays, then the bell as its supposed to, but all the sounds die immediately following. They come back on, but the primemover sounds go straight to high idle and the engine at this point after adding some more voltage may or may not move at all. The sounds continue to play and the engine just sits there. I read the DCC manual with it from soundtraxx and apparently the loco has a built in safety switch that will make all the lights strobe if the circuit board is being overloaded (this happens after I add the max voltage and the loco doesn't move.) I tried to hook the engine up to some cars while troubleshooting this, but it will barely move under its own weight! What the heck?! Has anyone else had any problems like this? BTW: my other engines, although they dont have sound work just fine!

-Richard Wongsing
 

Motley

Active Member
Why are you not running this on a DCC system? I think you're problem is trying to run it on DC.
 

fast_ian

Member
... I think you're problem is trying to run it on DC.
+1

I think you're being a little "optimistic" to expect it to behave under DC control - Particularly as it's no longer got default values set for various parameters.

And please don't do this again:

apparently the loco has a built in safety switch that will make all the lights strobe if the circuit board is being overloaded (this happens after I add the max voltage and the loco doesn't move.
:eek: Kudos to S/T for saving your ass here btw! :)

Good luck,
Cheers,
Ian
 

RW&C

N Scale with Stone Tools
Running DCC locos on DC is apparently pretty touchy. Supposedly it'll work, but it's a bit like running a computer on a car battery. It works fine if you're MacGyver and you're doing something awesome, but otherwise, it's not the best idea.
 

wongsing

Member
Well, the reason I am not running it on DCC is because there are no model railroad clubs around here that I could go to and because I am in the military and I don't own the house I live in (and will soon be moving out of) building a DCC layout would be pointless. I understand that these locos don't work THAT great on DC when they have sound, but I have owned several locos before that have had sound, ran on my oval DC setup with no problems. When I was at the hobby shop earlier the loco was doing a very similar thing on the DCC test track. Now guys, I was simply looking for some answers as to why the loco may be acting different than it did before. Again, it was fine the last time I ran it probably Wednesday or so....Okay, so adjusting CV's could make it not work as well with DC anymore...Ok, just trying to figure out how so many of my other locos that have had sound were equipped with momentum and real train inertia so forth and so on. This loco is advertised with a "dual mode decoder" so is it just me or is it supposed to be compatible with DC or DCC setups? Lastly, perhaps it was not noticed in my initial post that this loco was doing the same thing at the hobby shop and the gentleman there was noting that the engine appeared to have "an electrical short" as if the wheels were dirty. I have cleaned the wheels (although they are almost completely brand new still) and cleaned my track. The loco is still doing the same thing. Does anyone have any other ideas or has anyone else had a similar problem? Thanks!

-Rich
 

Motley

Active Member
The only thing I can think of is to reset the decoder back to factory defaults. If you don't have a DCC system, just go back to Caboose Hobbies and have them do it.

It sure sounds like after they "tinkered" with the CV settings was when you started experiencing the problems?

Also, if you spent $200 for this loco, you might want to pick up a cheap beginner DCC system and hook it up to your simple oval. It's easy to wire up, you don't have to change the wiring on the oval or anything. Just unhook the DC transformer and hookup the DCC system.

Trust us when we say it's not good to run DCC locos on DC, and vice versa. They simply just don't work well, you will always have problems.
 

fast_ian

Member
Hi again,

I (and I suspect the other posters) did indeed notice the comment from the guy in the store, but it doesn't really add up (!) - It seems the programming "took" in that the things you wanted changing did indeed change - Which is good. However, dirty wheels/track won't cause an "electrical short" - It may cause the programming not to take, but not a short.

"Dual mode" is, as has been noted, something of a misnomer - In default mode they'll lurch along on an analog track, but are missing so much functionality it's really not worth it - Particularly once the settings have changed.

Incidentally, do you know if the guy in the store used a computer & JMRI to do the programming? If yes, did he give you a print out of the settings now?

Having said all that, I have a little Bachmann EZ-DCC controller thats surplus to requirements that I'll happily send to you if interested (gotta support the military!) - IIRC, it'll only address lower end CV's so is not the best, but it may be a start in the right direction? [PM me your address etc if interested]

Good luck, cheers,
Ian
 

diburning

AlcoHaulic
Rich, if you just pick up a Digitrax zephyr or something, all you would need to do is hook it up the same way as the power pack. You can run DC on 00, and DCC for any other decoder addresses as well as being able to blow the horn, etc. The zephyr is the size of a book so it can be easily moved.
 




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