Howdy.
Atlas GP 40-2 N scale Lenz decoder factory installed new.
She was going along just fine and stopped where locos never stop on this set of tracks. MRC Prodigy blinking light spelled short "as I've seen before doing stupid things like turning on the power with metal crossing the tracks". Turned off the power. Removed shell from loco and smelled burnt money.
Checked the wheel sets and all were shorted together. Pulled them from the chassy and all were isolated as they should be. Other locos run fine.
Must be the decoder. Right?
Thanks, Scookam.
Check the motor contacts where they connect to the bottom of the decoder. They are known to shift and sometimes short or more likely just stop making contact. Lights will work but motor won't go. Decoder may not be damaged.
Martin Myers
Burnt smell on a decoder is never a good thing. Fried decoder is likely.
If it smoked, that would not necessarily be fatal. But burnt smell? Not good.
Rich
Alton Junction
Thanks guys.
Pulled the frame apart, which was also shorted side to side, and removed the decoder. Reasembled and sides and wheel sets no longer shorted. Cant see anything smoked on the decoder though.
Dont have a clue how to test a decoder so Ill just order a new one. First time for this part of the hobby for me. Think Ill get a NCE one instead of the Lenz. Have read here the MRC decoders dont fill the bill too well allthough I am fond of the MRC system I have.
Thanks again for helping me think out loud.
Ron
Did you try a full factory reset on the decoder, then reprogram or attempt to run? Always worth a try. More often than not, it doesn't fry in my experience, just needa a reset, but you could have had a bad day.
My Lenz experience is very limited so far, but on the programming track it will say something like "Cannot read CV..." if it's dead. It may say "Short detected..." which you need to solve first. You may find it dead or partially dead anyway, but most of the time once solved things work OK again.
Mike Lehman
Urbana, IL
Yup...
Sure looks like it to me!
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
That there is some funny stuff Lion! Looks like you spelled A 1 in the pan. Will this be the sauce we wash those down with? Yum.
Mlehman, Yours is a good idea however setting the loco on a hot track is a dead short.
My neighbor has an OTT light used for hobby close up work so I put my smokey cajun decoder under the big mag lens and did locate the fried object. A little black thing I will refer to as a "resistor"? with a small moulton hole in it and the solder connection.
I guess we call this closuer. Maybe Ill finish it off ala Lions recipe. With a nice whine of course.
Ron,
Well, that's gonna cost you, I guess. Doesn't the Prodigy do a Programming track? That's what I was thinking off, as it protects against meltdowns like yours by letting you check for shorts before it goes on the live track.
scookam My neighbor has an OTT light used for hobby close up work so I put my smokey cajun decoder under the big mag lens and did locate the fried object. A little black thing I will refer to as a "resistor"? with a small moulton hole in it and the solder connection.
I'm not surprised by this discovery. Unfortunately for me, I have fried a few decoders in my time. Whenever that burnt smell occurs, it has always meant a fried decoder. Sorry to hear about that.
mlehman Ron, Well, that's gonna cost you, I guess. Doesn't the Prodigy do a Programming track? That's what I was thinking off, as it protects against meltdowns like yours by letting you check for shorts before it goes on the live track.
Well, the programming track is definitely the place for a new install, to verify it works and there are no shorts in a current limited situation, but once everything tests out via programming, if a short happens to develop through vibration or wear while the loco is running, not much you can do about it.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
richhotrainUnfortunately for me, I have fried a few decoders in my time. Whenever that burnt smell occurs, it has always meant a fried decoder. Sorry to hear about that.
I gotta agree with Rich for the most part. On the other hand, don't give up hope until you're sure it's dead. I was fighting an intermittent short in one loco for awhile. Was back and forth betwen the layout and programming track. Finally, it seemed like I let the smoke out. I even saw the puff of smoke.
OK, that one's given up the ghost...
Was getting ready to tear it down, but an interruption caused me to forget which axle the visible symptom came from. So went to put it on the track briefly enough to feel the heat from the short so I could determine the problem area. Put it back on the track...
The lights came back on!!? Which led to this teardown anyway: http://cs.trains.com/mrr/f/88/t/231131.aspx
This was surprising to me, especially after having seen smoke and based on past experience...maybe it's a zombie loco???
rrinkerWell, the programming track is definitely the place for a new install, to verify it works and there are no shorts in a current limited situation, but once everything tests out via programming, if a short happens to develop through vibration or wear while the loco is running, not much you can do about it.
Randy,
True, but since the OP made no mention of using the programming track, I suspected maybe that step was omitted.
As my previous comment just above noted, you can also get the apparent symptoms of a decoder fry, down to the smoke, and still have a good decoder. That thing has shorted -- only briefly, but definitely a short -- numerous times over the last six months.
These shorts obviously didn't fry the decoder, but jiggling things on the way to the programming track may have disguised the short once it arrived there. There are the shorts that fry your decoder (or parts of it) and then there are shorts which simply ground one rail to the other somehow, in the process taking a short-cut (bad pun, I know) around the decoder and leaving it intact.
scookamA little black thing I will refer to as a "resistor"? with a small moulton hole in it and the solder connection.
More likely a diode. If you knew the value of it, you *could* replace it. LION has salvages some flat screen monitors that way (blown capicators, you know... those are easy to see and fix).