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Signs of a fried decoder

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  • Member since
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  • 42 posts
Signs of a fried decoder
Posted by anthonykaz on Saturday, December 27, 2008 10:26 AM

What are the signs of a bad decoder?

My locomotive will move, I can turn the light on and off, but there is a buzz coming from the motor and the rear headlight will shine at half power when moving forward. When I had no decoder and dcc power, the motor would make the same buzzing sound, and the lights would be on. I have checked for shorts and anything I can think of.

Please help if you can,

AK

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  • From: Western, MA
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Posted by richg1998 on Saturday, December 27, 2008 10:49 AM

How about some information?  Loco brand, scale, DCC controller. decoder brand, are you trying to run a decoder equipped loco on DC? If you are trying to run a loco on DCC with no decoder, the motor is going to buzz. DCC contollers send pulses for control.

It sounds like you need a primer concerning DCC.

http://www.members.optusnet.com.au/nswmn2/DCC.htm

Rich

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Posted by jeffrey-wimberly on Saturday, December 27, 2008 11:04 AM

 Do you mean to say that you are running a DCC equiped loco on DCC and it's making these noises? How old is the decoder? It may not be a 'silent drive' decoder. If that's the case it's going to make noise no matter what you do. As for the problem with the rear light, some decoders do that for some reason or other. I have a few that the rear light stays on full brightness no matter what but the decoder operates normally in all other respects.If your decoder was fried the loco wouldn't run at all. If you have one that suddenly fries while in operation the loco will put any Alco to shame for a couple of seconds.

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Posted by cacole on Saturday, December 27, 2008 11:50 AM

 More iinformation would help us advise you.  What scale?  What brand and type of decoder?  What type of DCC system? 

As already stated, the engine would not run at all if the decoder was fried.  As far as the light is concerned, it sounds like the decoder is programmed for "Rule 17" lighting wherein the headlight and/or backup light dim when the engine is operated in the opposite direction.  This can be cured by CV programming, so you need to delve into your decoder's instructiions to change this.  And all this assumes that you have a DCC system that can program decoders.

 

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  • From: Mo.
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Posted by armchair on Saturday, December 27, 2008 12:57 PM

 Sounds like this loco had issues to begin with . Putting in a decoder won't solve mechanical problems . Like someone else mentioned, if the decoder was fried, the engine won't move . You didn't say what the brand is & i'd best not guess.

anthonykaz

What are the signs of a bad decoder?

My locomotive will move, I can turn the light on and off, but there is a buzz coming from the motor and the rear headlight will shine at half power when moving forward. When I had no decoder and dcc power, the motor would make the same buzzing sound, and the lights would be on. I have checked for shorts and anything I can think of.

Please help if you can,

AK

  • Member since
    July 2007
  • 42 posts
Posted by anthonykaz on Saturday, December 27, 2008 4:14 PM

INFO:
Bachmann GP-40 HO scale worked perfectly before decoder install, no noise

Dynamis controller

MRC AD350 6 function decoder

The manual says that it follows Rule #17, so that will not be an issue.

I hope this helps you

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Posted by locoi1sa on Saturday, December 27, 2008 5:36 PM

 Thats your problem! Rip the MRC decoder out and put in a TCS,NCE,or Digitrax silent drive decoder. You realy dont need a 6 function decoder if your not hooking up ditch lights. If you do do ditch lights than go with the NCE decoder. They seem to have the best ditch light software. Another thing you might consider is a decoder with Back EMF for realy slow speeds and motor control.

    Pete

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Posted by cacole on Saturday, December 27, 2008 5:44 PM

 Yep, the problem is the lousy MRC decoder.  Take it out and put a real decoder into the locomotive and your problems should all be solved.  A TCS, Digitrax, NCE, or Lenz would be a much wiser choice of decoder.

 

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Posted by maxman on Saturday, December 27, 2008 6:21 PM

cacole
Yep, the problem is the lousy MRC decoder

While this very well could be true, is there not some way he can test something to be sure it is the decoder, rather than something that got mis-wired?

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Posted by maxman on Sunday, December 28, 2008 12:58 PM

davidmbedard
A great way to test is to take out the MRC decoder and put in something worth while.

Yup, that would be correct.  And it is probably likely that the decoder could be the problem.  But if the existing decoder is not the issue and he has some other problem, then he has paid for something he doesn't need.  The OP asked for help.  When he finally got to the point where he said he had the MRC decoder, the default answer became that the decoder was the problem.

All I'm asking is that if he had said that he had a NCE, TCS, or Digitrax decoder, would he have received the same advice, or would there have been some investigative advice?  If the advice would have been the same, then fine.  If not, he did not receive a good response from the people here who are supposed to know.

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Posted by mfm37 on Sunday, December 28, 2008 1:06 PM

 If you have control of it with DCC  e.g. Runs forward and reverse on command, lights turn on and off, the decoder is not burned.

If your motor made noise before the decoder, it will make noise after installation. The decoder just runs the motor instead of the track running it. Can't comment on the quality of MRC decoders except that I've never had the need to own one. There has always been something else with more features for the same or less $$.

 Martin Myers

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Posted by maxman on Sunday, December 28, 2008 2:13 PM

davidmbedard
That isn't fair.  You didn't completely quote me.

Sorry, I didn't include this statement because I was trying to be unfair or fair.  I left it out to save space as I was not responding to that portion of the response.  Yes, checking with a multi-meter is good advice.  But checking what, where?  I looked at the instructions for the decoder that was used, and it requires the user to make the connections.  It is not the plug-in variety.  To me it appears that there is room for error with the connections.  But that is as far as my knowledge of problems extends. 

I again ask the question, if the decoder was some other brand would the advice be to replace the decoder?  Or is the answer still to check for shorts?  If that's the answer, then that's fine.

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Posted by anthonykaz on Sunday, December 28, 2008 4:24 PM

I got the stupid thing working, just a small short on the bottom of the pc board of the decoder to the frame. A piece of electrical tape on the bottom fixed the problem.

Thanks for all of your help

AK

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