Help me troubleshoot this decoder--final (almost) resolution 5-16

[n2mopac]

I was testing some newly layed track last night with an Atlas GP40-2 with a digitrax decoder (N scale) that I have had on hand and run quite a bit over the past year with no problems. Last night things were going great when suddenly the loco stopped and the rear headlight came on (I had been running forward) and I could get no response from the locomotive. My system is MRC's Prodigy Advance. I'm pour over the literature, but perhaps you can help me out. Did I blow this decoder or is this some issue that can be solved short of sending the decoder to Digitrax repair?

Ron

[Anonymous]

My 1st thought was it was a Brainfart, something I have seen decoders do every now and then. Did you try tipping the engine up so that one side is off the rails for about 10 seconds or so. I've had this "fix" the occasional decoder from time to time. (Not trying to throw flames here, but I've only seen it with Digitrax decoders).
Have you tried putting it on a programming track and try to read CV's?? Can your system perform a factory reset of all CV's? (I'm not familiar with the MRC systems)
If none of the above help, pop off the bodyshell and inspect the shrink wrap on the decoder for discoloration, and best of all, smell it. If it smells like burnt toast, it's probably cooked.[V] Start looking for shorts in the engine.

[Anonymous]

I'm new to DCC and all I know is what I've read. Is it possible the decoder lost its CV settings or reset itself?

[Bill54]

I haven't seen one stop while the engine was running but I did have one loco lose it's ID for what ever reason after sitting for a month. I put it on the programing track and re-programed it and it worked fine.

I'd go along with first trying to reprogram it. If that doesn't work I'd take the shell off and look further.

Bill

[n2mopac]

I did take the shell off right after it happened and could not see nor smell any obvious signs that is had overheated/melted as if shorted out (and trust me, I have some experience in that area, but that is another story altogether). I will try reprogramming it tonight and I'll let y'all know if that works. Thanks for the input.

Ron

[greendiamond]

Ron:

If you can control your headlights by changing direction and just lost motor control, the two brass motor contacts are no longer making contact with the decoder. If this is your problem, remove the decoder, bend it slightly and put it back it and try it. IF that solves your problem, you can either leave it in until it happens again or your can remove it and solder short pieces or wire from your decoder to those motor contacts.

[n2mopac]

Ok, here is an update. When I went back to it last night the headlights did not come on, but they flash on every time I put the loco on the track or wiggle it a little. At one point as I playet with it it took off and ran forward about 2 feet. I stopped it, reversed it, it ran back a couple of feet, then stopped and did the same thing. Acts like a bad electrical connection to me, but for the life of me I cannot figure out where. I cleaned all of the pickups. Suggestions?

Ron

[Anonymous]

I know this sounds crazy but did you clean the track and the wheels???? Even if dirt and grime isn't visiable it still could be the issue.

QUOTE: Originally posted by n2mopac

Ok, here is an update. When I went back to it last night the headlights did not come on, but they flash on every time I put the loco on the track or wiggle it a little. At one point as I playet with it it took off and ran forward about 2 feet. I stopped it, reversed it, it ran back a couple of feet, then stopped and did the same thing. Acts like a bad electrical connection to me, but for the life of me I cannot figure out where. I cleaned all of the pickups. Suggestions?

Ron

[Bill54]

jflessne has a good point. Clean the track and wheels and give that a try.

If it still acts up, check the wires anywhere they are exposed to movement. I've had wires break inside the insulation and you can't tell it by looking at the wire. If it's possible flex each wire every 1/4 inch. If you find a space that bends too easily or is flat when bent then you may have found the broken area.

Bill

[Anonymous]

QUOTE: Originally posted by n2mopac

..... it took off and ran forward about 2 feet. I stopped it, reversed it, it ran back a couple of feet, then stopped and did the same thing. Ron

Ron, do you mean it ran forward until you stopped it or it ran forward and stopped on its own? If doesn't turn out to be dirt on the track and wheels (most likely), check the power to the rails.

You wouldn't by any chance have a playful kitten in the house that likes to chew on or bat around wires do you?

[modelalaska]

I had a digitrax decoder w/ similar problems... though it never ran the loco, the lights blinked on and off with a bzzzit sound. I had to send it in and Digitrax replaced it.
This sounds like a short but it could also be a malfunctioning decoder.
Peter

[n2mopac]

QUOTE: Originally posted by Bill54

jflessne has a good point. Clean the track and wheels and give that a try.

If it still acts up, check the wires anywhere they are exposed to movement. I've had wires break inside the insulation and you can't tell it by looking at the wire. If it's possible flex each wire every 1/4 inch. If you find a space that bends too easily or is flat when bent then you may have found the broken area.

Bill

This is a replacement light board decoder made specifically for this series loco, so there are no wires, just direct connection points between the frame and the board.

Ron

[n2mopac]

QUOTE: Originally posted by gsetter

QUOTE: Originally posted by n2mopac

..... it took off and ran forward about 2 feet. I stopped it, reversed it, it ran back a couple of feet, then stopped and did the same thing. Ron

Ron, do you mean it ran forward until you stopped it or it ran forward and stopped on its own? If doesn't turn out to be dirt on the track and wheels (most likely), check the power to the rails.

You wouldn't by any chance have a playful kitten in the house that likes to chew on or bat around wires do you?

I wasn't very clear there, sorry. I had the throttle set to go forward at moderately slow speed. When it finally took off, I throttled it back to a stop, reversed it, throttled up and it ran in reverse for almost the same distance, then stopped on its own again and we were back to the same symptoms as before.

I know now that it didn't lose programming as it responded to the address I had programmed. As stated above, I may simply have to send it back to Digitrax. Their service department is pretty good about taking care of their customers in my limited experience.

Ron

[Anonymous]

One other thought. does the engine run on DC (if the decoder is set for it) ??

If not, then the issue may be the loco, not the decoder.

[Adelie]

Ron,

This sounds eerily familiar to me. I'd second Greendiamond's suggestion earlier about verifying that the brass contacts from the motor are actually making solid contact with the contact points on the decoder. Those contacts are the achilles heel of the Atlas system. They bend out of shape fairly easily, and even will slip a little forward or behind the decoder contact points. IWhen they do, you get lights and no motor. I installed decoders in 5 Atlas RS11s a couple of weeks ago and did that battle with 2 of them, as well as an SD7 that somebody installed a decoder in that did not run. It was the same problem in every case.

[Anonymous]

I still think it's a dirty connection rather than a faulty decoder....It happens at our module club shows. Especially towards the end of the day. Some locos have no trouble with the track being clean or not. For example.

A little story.
I was running a friends SP steam local for about an hour. Flawlessly runs around the 46 x 64 layout. Everyone else seems fine then bam I start stalling on someones module. No one else was...gave it a little push and it continued on. Came back around same thing. Ran a cloth of alcohol over the area and it ran fine again. I asked why when it stops the head lamp was still on...the answer...I guess it still is getting enough juice to light the light. Made sense to me anyway.

Also thought of something else. My friend has a large basement layout. He had similar problems and discovered he had a dead feeder wire. Just thought I would mention this.

[n2mopac]

Tonight I'm going to tripple check the contacts with the decoder, reclean the wheels and track and add a touch of cliipper oil to the track (this always helps electrical contact) and I will report back tomorrow. Thanks for the suggestions all.

Ron

[n2mopac]

Ok, guys. It took a couple of days, but over the weekend I thoroughly cleaned the track and the wheels, I tripple checked to brass connectors to the decoder as well as the connections of the decoter to the frame for electrical pickup. I put a little chipper oil on the track for electrical conductivity and not change. I have decided it must be a decoder issue. I contacted Digitrax repair dept. on Fri. but have not heard back yet. I'll kee you posted.

Ron

[jsoderq]

I am not n scale but I know there is an issue with the wrong speed step with some decoders. Can't remember , but if the base is set to the wrong speed step, the light comes on but the loco won't move.

[n2mopac]

QUOTE: Originally posted by jsoderq

I am not n scale but I know there is an issue with the wrong speed step with some decoders. Can't remember , but if the base is set to the wrong speed step, the light comes on but the loco won't move.

I have tried using all of the speed step options and this has not made a difference. Besides, it started this mid motion. Thanks for the idea though.

Ron

[Anonymous]

Ron
Have you tried a different loco on the track just to be sure it has nothing to do with the track? It could very well be just a bad decoder but I just can't help thinking it's a loose or frayed wires in the power pickup on the track.

[modelalaska]

QUOTE: Originally posted by n2mopac

I was testing some newly layed track last night with an Atlas GP40-2 with a digitrax decoder (N scale) that I have had on hand and run quite a bit over the past year with no problems. Last night things were going great when suddenly the loco stopped and the rear headlight came on (I had been running forward) and I could get no response from the locomotive. My system is MRC's Prodigy Advance. I'm pour over the literature, but perhaps you can help me out. Did I blow this decoder or is this some issue that can be solved short of sending the decoder to Digitrax repair?
Ron

Ron, I just had the same thing happen to me last night except with my Bachmann GP40 with a Digitrax Decoder. I was about to disassemble and then I thought I would try to re-program on the programming track. I did and it is running just fine now. Guess the decoder lost its mind.
Peter

[n2mopac]

To respond to the past two ideas shared, 1) This is a brand new section of trackage that I just wired and the voltage tests perfectly on my ammeter, so I do not believe track wiriing is the problem. 2) I tried reprogramming the decoder and it would not accept reprogramming. I simply won'ty respond on the main or on the programming track. It won't even let my system read the CV's on the programming track. The one bried moment that it did respond, however, it responded to the address that I had programmed in. Thanks for your input.

Ron

[n2mopac]

I thought I would update this thread. I sent the decoder to Digitrax and they said it was not working and unrepairable. They sent me a new one. I havn't installed it yet (just got it today) but this concerns me a bit. Has anyone heard of others having problems with MRC's Prodigy Advance burning out Digitrax or other decoders? I don't want to jump to conclusions but I want to be on the safe side here. I don't reallly want to pay another $17 to replae it again.

Ron