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Problems with Atlas HH660 Locos and rolling stock
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Active Member 61 posts aileron44 Active Member 61 posts
aileron44

Hi one and all,

Well, it's taken me a while but I finally set up a test track connected to a Digitrax Zephyr.  I've run a few used/old DC locos and most everything works fine but I have one big issue. The Zephyr is set to address "OO" for DC motors.  The throttle is set to stop and the brake is on. Track power is off.  I positioned an Atlas HH660 (Silver - new, with no decoder - never run) right out of the box onto the test track.  

When I push the button for track power, the track status light comes on but the digital display indicates a short circuit (scrolling zeros across the digital display).   Simultaneously, the light in the loco pulses every second and the motor makes a noise as if it wants to run. 

When I push the button to turn track power off, the track status light gets brighter and the loco runs rapidly along the track until i push the track power button a second time.  The track status light finallyl goes out and the loco stops running.

Thinking that perhaps this loco somehow might have a decoder in it, I changed the address to "03" and then "1003" (engine number) but the same issues occurred as above.

Using a VOM, I performed a continuity check from wheel to wheel.  It appears that all eight wheels are making contact.  I've checked other locos and found that at least one wheel should be insulated from the others. 

Is the motor short circuited internally right out of the box?  How are wheels insulated in the trucks?  How many wheels should be insulated in this loco?  How do I remove the shell?

Can someone with way more knowledgeable about Zephyrs and small HO 4-axle diesels please help me figure this issue out or suggest how to proceed?

Thanks,

George
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Mark R. Regular poster 293 posts
Mark R.

Won't Work ....

Sounds like a DC engine with no decoder. Atlas purposely places a low value resistor on the DCC dummy plug that a DCC system will see as a short. This is to prevent you from running the engine with a DCC system set to address 00. Too many people were damaging motors doing this and this was a way of helping to curtail the problem. 

It really isn't a good idea to run DC engines on your DCC system. A lot of the more recent DCC systems won't even allow you to access address 00 and model manufacturers are starting to add the shorting resistor to prevent you from doing it as well. A rep. from Atlas said they were getting way too many engines back that were damaged from just that.

Mark.
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aileron44 Active Member 61 posts
aileron44

Re: Won't Work

Thanks Mark for you insight. 

I should have included that this is supposed to be a Silver Master Series loco that is "DCC Ready" with 8-pin socket but no decoder.  So it should run as a DC loco.  I only tried it on DCC as a shot-in-the-dark.

My guess is that since the loco runs but not the appropriate way, the motor is not short circuited but must be something wrong with the wheels or trucks not being insulated properly.

George
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Mark R. Regular poster 293 posts
Mark R.

It IS Correct

The silver series have a dummy plug in the 8-pin socket. There is a tiny surface mount resistor on this plug that is there to prevent you from running on your DCC system using address 00. It will work just fine with a standard DC power pack. I don't see anything wrong with your engine based on your description.

Mark.
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aileron44 Active Member 61 posts
aileron44

Re: It IS Correct

Thanks, Mark.  I think I'm beginning to understand.  From what I could gather, the Zephyr on address 00 is DC mode but really it is pulsed AC and some locos don't like this.  Apparently, I have some that do and some that don't.  I'll try running this one on straight DC and see what happens.
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