Testing a Decoder

[Peter749]

I have a Model Rail/Rapido J70 which runs ok and I want to put a DCC Decoder in.

The one I purchased is a Bachmann branded 6 pin but is made by Zimo

 

Another poster noted the pins are too long for the socket so I shortened them

But I cannot seem to make the loco respond to the controller on the default #3

 

So it there a way I can test a decoder to see if it works as it should?

Otherwise it is a lot of money to put in the bin

 

Peter

[gordon s]

The ESU decoder tester is a useful piece of kit to check decoders. At £38 it’s not cheap if you are only testing one or two decoders, but for a large roster it can save a lot of time checking things.

 

https://www.coastaldcc.co.uk/products/esu/53900-decoder-tester

[Ray H]

Have you fitted the decoder the correct way around?

 

Have you inadvertently clipped too much off the pins?

 

Do you have a test meter that would let you check for continuity between the decoder body and the equivalent socket on the loco?

[Peter749]

On 07/09/2020 at 19:43, Ray H said:

Have you fitted the decoder the correct way around?

 

Have you inadvertently clipped too much off the pins?

 

Do you have a test meter that would let you check for continuity between the decoder body and the equivalent socket on the loco?

[1] The Decoder is the correct way round

 

[2] I don't think I have clipped off too much from the wires

 

[3] I have a test meter but I have no idea how to test the continuity between the decoder body and the equivalent socket on the loco

 

What does not help is the pins on the blanking plug are fatter than those on the Decoder which makes the Decoder sloppy

 

Peter

[Peter749]

On 07/09/2020 at 19:43, gordon s said:

The ESU decoder tester is a useful piece of kit to check decoders. At £38 it’s not cheap if you are only testing one or two decoders, but for a large roster it can save a lot of time checking things.

 

https://www.coastaldcc.co.uk/products/esu/53900-decoder-tester

I think I'm getting one of those - with the cost of Decoders in the 20 - 30 quid range I have three which don't seem to work as they should

 

Thanks

 

Peter

[Neils WRX]

The decoder tester is a great piece of kit.

 

In the short term do you have another loco that has the same 6 pin socket you could test the chip in ? As occasionally chips are faulty.

 

Stay safe,

 

Neil

[Nigelcliffe]

37 minutes ago, Peter749 said:

[1] The Decoder is the correct way round

 

 

Have you tried the other way round ?   Its a really common mistake with 6-pin decoders, often amplified by poor labelling in either loco or on decoder.  

 

 

[Ray H]

2 hours ago, Peter749 said:

. . . . 

 

I have a test meter but I have no idea how to test the continuity between the decoder body and the equivalent socket on the loco

 

What does not help is the pins on the blanking plug are fatter than those on the Decoder which makes the Decoder sloppy

 

Peter

 

Do you know how to test for continuity between the tips of the two probes - in other words can you set the meter's (knob) pointer to a specific position so that you get a reading (or audible sound) when you touch the tips of the two probes together?

 

A sloppy fit may be the cause of your problem as you have no guarantee that all the pins are touching the relevant sockets. I'd suggest slightly bending the pins just enough so that there is friction when you push the decoder into the socket. I'm only talking a few degrees maximum. Try it on one pin and then repeat the process on the other 5 pins and re-check whether to decoder is working.

[BernieL]

20 hours ago, Peter749 said:

[What does not help is the pins on the blanking plug are fatter than those on the Decoder which makes the Decoder sloppy

 

Peter

I have exactly the same problem.  The pins on the Bachmann 6 pin decoder are much thinner than the blanking plug of the DJ models 1361 loco.  The decoder is a very loose fit and needs a jiggle to get it working.  Then the loco stops frequently on rail joiners as this seems to jiggle it loose again.

 

17 hours ago, Ray H said:

I'd suggest slightly bending the pins just enough so that there is friction when you push the decoder into the socket.

Thanks a good tip, I will try this and let you know,

Bernie.

Everyone has their share of mistakes, I am just greedy.

[Peter749]

On 09/09/2020 at 15:05, Neils WRX said:

The decoder tester is a great piece of kit.

 

In the short term do you have another loco that has the same 6 pin socket you could test the chip in ? As occasionally chips are faulty.

 

Stay safe,

 

Neil

I ordered the Decoder tester and it arrived today - Thursday.

I will get a chance to try things tomorrow

 

Peter

[34theletterbetweenB&D]

On ‎09‎/‎09‎/‎2020 at 17:31, Ray H said:

...A sloppy fit may be the cause of your problem as you have no guarantee that all the pins are touching the relevant sockets. I'd suggest slightly bending the pins just enough so that there is friction when you push the decoder into the socket...

Alternative  'cheap and dirty' fix from the olden days, a little dab of solder on each pin end. Much used to make valves stay in contact in sloppy sockets - that dates me - off to wheeltappers with that little gem.

[Right Away]

On 09/09/2020 at 14:48, Peter749 said:

 

 

 

 

 .... What does not help is the pins on the blanking plug are fatter than those on the Decoder which makes the Decoder sloppy.

 

 

 

You might try very carefully creating a gentle curve in the pins to create a side pressure in the socket.

I must admit when faced with this kind of problem I replace the whole NEM651 set up with a hard wired decoder with “tails” thus eradicating any loose contact issues. It’s not cheap having to buy another decoder and we don’t expect to have to resort to this.
I had a similar issue with a 21 pin set up, the loco suddenly stopping and starting. Exchanging the decoder didn’t work therefore I removed the lot and hard wired a Lenz Standard 8 pin with wires. Beautiful!

 

[Peter749]

I'm not up to hard wiring a Decoder but there is a chap locally who does such things and as I have another loco waiting for a decoder I might give him a call

 

Thanks for the idea

 

Peter