Bachmann Online Forum

Discussion Boards => HO => Topic started by: smvirr on March 11, 2016, 11:41:50 AM

Title: DCC on board decoders.
Post by: smvirr on March 11, 2016, 11:41:50 AM
I have bought 4 G.E. 70 ton locomotives.  Two of the decoders stopped functioning during the break in run.  I replaced them with digatrax decoders.  Has any one had problems with the factory installed decoders?
Mike
Title: Re: DCC on board decoders.
Post by: Ckrails on March 12, 2016, 04:09:47 PM
Mine (also 70 tonner) burned out when it short circuited the first time.  Easy replacement though with another OEM decoder, and it has been running fine for a while.

How Does it perform with the the Digitrax relative to the Bachmann decoder?
Title: Re: DCC on board decoders.
Post by: electrical whiz kid on March 15, 2016, 07:06:21 AM
If you guys are running this stuff sans any overcurrent protection, you are asking for trouble.  Get your circuit breakers incorporated with your power supply systems.  Also, make sure your track is clean-no junk on the rails that might cause problems.

Rich C.
Title: Re: DCC on board decoders.
Post by: brokenrail on March 18, 2016, 10:22:09 PM
Most good decoders have some type of protection that shuts them down rather then frying .I have seen many times actually do to the weather and the tight packaging they use . Condensation builds up on the circuit boards and will cause strange operation like over current or a short or lack of direction control and most times all is needed is the loco to sit out and dry  and then the decoder on-board to be reset.These on-board decoders are pretty tough customers.Have had many over the years and have not had a failure.They are basic as you can get but tough.Probably why Bachmann uses them.Did you try to reset them before you replaced ?
Johnny Adam
Title: Re: DCC on board decoders.
Post by: electrical whiz kid on March 19, 2016, 09:08:04 AM
Broken Rail Et Al;
A couple of things to keep in mind with electronics:  Moisture on that board can occur; and if it does then some short-circuiting can likely happen, more so as per the higher command frequencies are called upon.  Those higher frequencies can act just like high voltage in that respect; and can raise holy merry hell with the close-proximity of devices and resistors, etc.; this can readily exacerbate this already touchy problem.
In the industrial sector, the newer sophisticated proximity sensing electronics embedded with-in over-current/under voltage protection can do some pretty "snazzy" things...  For instance,I've gone out to a customer's factory and have found boards covered with 'swarf'; this is a mixture of cutting coolant and tiny metal chips-in this case- collecting on a board, usually because some 'genius' has left an enclosure uncovered, or some other relative collection of stupidity.  I have found this-and EXPLOSION-PROOF JUNCTION BOX covers left off in a 'class-one/division one' environment!  Gives much credibility to "suits", etc...  Right on down the line.  Stupid is as stupid does, I reckon...
The higher 'command' frequencies work very similar to an 'AM' signal; that is, two components present; the control, and the carrier frequencies.  The rest should be apparent.  One trick I have for stuff like this is conductive foam.  If you have ever used CMOS semiconductors, you will know about this stuff.  I try to use it in like a shield, so far, so good.  With nominal voltages(480, 600, etc.), I will bond it to a grounding system; in dcc applications, I just leave it somewhere over the board where it acts like a protective shield.

Rich C.
 
Title: Re: DCC on board decoders.
Post by: Bucksco on March 19, 2016, 10:11:56 AM
As others have stated there are a lot of variables involved. The standard motor decoders in Bachmann locos have been around for a long time and have a very good track record. Before jumping to the conclusion that the decoder is bad you should check the other possibilities starting with your power source.
Title: Re: DCC on board decoders.
Post by: electrical whiz kid on March 19, 2016, 07:56:31 PM
Yardmaster;
To cover myself, I was not inferring that ANY top-quality board is prone to failure.  What I stated was only my experience with semiconductors in general-and 50 years of working with his stuff.
To be sure, this can be something to keep in mind...HOWEVER; The simplest stuff-again in my experience as an electrician-usually makes the biggest noise in it's quest for attention! This is the place I start looking-the simple stuff.  Unplugged stuff, broken/poor solder connections, etc.  I like simple...easy...

Now, to cover YOU:  In the years I have been in HO standard gauge, I have been more than satisfied with Bachmann and the staff I have come into contact with. 
Rich C.
Title: Re: DCC on board decoders.
Post by: rogertra on March 21, 2016, 04:53:25 PM
Quote from: Yardmaster on March 19, 2016, 10:11:56 AM
As others have stated there are a lot of variables involved. The standard motor decoders in Bachmann locos have been around for a long time and have a very good track record. Before jumping to the conclusion that the decoder is bad you should check the other possibilities starting with your power source.

I agree, I have a dozen or so Bachmann decoder equipped diesels and steam and they are perfect for the job they were designed for.  I've not had a single one fail.


Cheers


Roger T.

Title: Re: DCC on board decoders.
Post by: electrical whiz kid on March 21, 2016, 08:03:26 PM
Roger;
I as well.  What Bachmann carries is pretty good stuff.  You do this in order to stay afloat in a very discretionary-money based business.  A little to portside:  I had mentioned conductive foam earlier.  A long time ago, I was trying to build a project out of Craig Anderton's 'Electronics projects for guitar Players', and had to work with CMOS semis.  It must have been very dry in the house that day, because after removing that foam; as soon as my hand touched the pins, I heard a definitive 'SNAP'.  I never went near a CMOS semiconductor again!  Craig's book was still good though...

Rich C.
Title: Re: DCC on board decoders.
Post by: plint on March 22, 2016, 09:35:42 AM
Quote from: smvirr on March 11, 2016, 11:41:50 AM
I have bought 4 G.E. 70 ton locomotives.  Two of the decoders stopped functioning during the break in run.  I replaced them with digatrax decoders.  Has any one had problems with the factory installed decoders?
Mike
Just curious.  If they were new,  why didn't you return them?