Bachmann 36-571 Decoder : Dead?

[Blobrick]

I am wondering if anyone else has had a similar problem?  I have a couple of Bachmann's Quarry Hunslet tanks, which after running in, l wanted to fit a suitable decoder to. I have acquired a Bachmann 36-571 6 pin decoder which l fitted to one of the locos. To my surprise , when l selected the default address of number 3 and applied power nothing happened.  I removed the decoder and checked it was the correct way up, reinserted it again, still no movement.

I have a basic controller (Bachmann EZ type)  with 10 addresses, l worked my way through them thinking that maybe the decoder was set to a differant address. Still no responce. I re installed the blanking plate and tested the model on DC with no problems. Tried the Decoder again and the model still refuses to move.

Have l done something wrong or missed something?  Anyone got any ideas?

 

Bob C

[WIMorrison]

I suggest that you try resetting the decoder to default and trying again. Even better if you have a decoder tester to plug it into (or another loco as a last resort).

 

These decoders are actually Zimo MX616 under the Bachmann label and extremely reliable.

[34theletterbetweenB&D]

This is the moment when a DCC  'full system' is very useful.

Unfortunately a minor wiring fault that applies DCC track power to the motor will kill the decoder if given track power, and that only requires one of the track power inputs on the socket or decoder to be connected to a motor power output, which causes no problem in DC operation. That usually results in component burn out on the decoder with the associated smell.

A full system supplies a programme track with very restricted current output only when  programming, to protect the decoder from damage from this cause, and will report a defect code.

 

There are other possibilities for what you have seen, a broken connection in the socket or on the decoder for example, and a full system will then report that it cannot detect a decoder.

 

One obvious test on the decoder is to try it in another mechanism. If it responds as expected then the problem - whatever it may be - is likely on the first loco it was tried on.

 

[Blobrick]

6 minutes ago, 34theletterbetweenB&D said:

This is the moment when a DCC  'full system' is very useful.

Unfortunately a minor wiring fault that applies DCC track power to the motor will kill the decoder if given track power, and that only requires one of the track power inputs on the socket or decoder to be connected to a motor power output, which causes no problem in DC operation. That usually results in component burn out on the decoder with the associated smell.

A full system supplies a programme track with very restricted current output only when  programming, to protect the decoder from damage from this cause, and will report a defect code.

 

There are other possibilities for what you have seen, a broken connection in the socket or on the decoder for example, and a full system will then report that it cannot detect a decoder.

 

One obvious test on the decoder is to try it in another mechanism. If it responds as expected then the problem - whatever it may be - is likely on the first loco it was tried on.

 

Hi there thanks for replying. I do have another  dcc (factory fitted)  loco which seems to work correctly on the existing layout.   I m now wondering about  the  DCC socket on the loco itself. I had discounted this initially as the model ran correctly on DC using the blanking plug, but thinking about it, the blanking plate only connects the motor feds so the other pins could be defective in some way, becoming apparent only when the decoder is plugged in.

I have another Hunslet tank l ll try the decoder in, l had not tried that option hoping l d done something silly in the first place?

 

Bob C

[jaym481]

If it runs OK on DC with the blanking plug in it should run on DCC even if the other functions are not working correctly. Did you get the 36-571 new? If not, the address may be changed and it will need a reset as @WIMorrison mentions above. Not sure if the EZ Command system can even do that though. As for installing it correctly, there should be some indication of what Pin 1 is on both the socket and the decoder. 

[Blobrick]

Hi there, yes the Decoder was bought new.  I did attempt to change the address from the default number 3, but the EZ system could not talk to the decoder in any way shape or form. So the only option at the moment is try it in another loco. As l mentioned earlier l was hoping l d forgotten something or done something daft.  Alas it appears not.

 

Bob C

[Nigelcliffe]

2 hours ago, Blobrick said:

.....

I have a basic controller (Bachmann EZ type)  with 10 addresses, l worked my way through them thinking that maybe the decoder was set to a differant address. ......

 

The only thing you can do with the EZ is reprogram decoder to a short address between 1 and 9.   (Or put it in the waste bin and get a decent DCC system). 

 

Reports so far suggest a fault, but unclear if its a loco or a decoder fault.   There are scenarios for both which fit the reported behaviour.  

 

- Nigel 

 

[Kaput]

The pickups on the Quarry Hunslet aren't the greatest for DCC, mine is a bit of a nightmare to try and program and ran like crap until a stay alive was fitted.

[WIMorrison]

Please explain why you need different, or better, pickups for DCC compared to DC and what the benefits are.

 

It would also help the OP if you detailed exactly how you improved the pickups on your quarry Hunsletts which made them run better.

[Kaput]

Its not brain surgery, DCC is is fussier with quality of electrical pickup and I never said anything about improving the pickups on mine, said I got a stay alive fitted.

 

Adjusting the pickups didn't really help and its still 50/50 whether any given attempt to read or write cv's on the programming track will work.

 

Going by the Quarry Hunslet thread in the Bachmann section its not uncommon for the alignment of the pickups to be poor.

[WIMorrison]

1 minute ago, Kaput said:

Its not brain surgery, DCC is is fussier with quality of electrical pickup and I never said anything about improving the pickups on mine, said I got a stay alive fitted

 

That is totally incorrect statement.

 

The "stay-alive" you have fitted will have masked the effects of a track voltage which may be too low and possible poor track. Quarry Hunslets have extremely short chassis which together with a low mass require that track laying is extremely good.  "Stay-alives" only ever mask problems, they never cure problems.

 

It is also the case that many people run the track at too low a voltage, forgetting (or possibly unaware) that the mythical 12v of DC which they like to run the track at, is reduced by around 2v by the decoder. DCC should be using a track voltage of 14-15v DCC to overcome that limitation.

 

[Izzy]

 

11 hours ago, Blobrick said:

Hi there, yes the Decoder was bought new.  I did attempt to change the address from the default number 3, but the EZ system could not talk to the decoder in any way shape or form. So the only option at the moment is try it in another loco. As l mentioned earlier l was hoping l d forgotten something or done something daft.  Alas it appears not.

 

Bob C

 

I find with the odd ‘fussy’ loco on a program track that it is helpful to physically hold them down to ensure proper contact. Did you try running the loco with the decoder at the default address before attempting to change it? Always a good idea to do that first with a new decoder. I do wonder if the attempt to change the address has sent a scrambled signal that the decoder read as something else and it does need a re-set. Shame your system can’t do that. 

Bob

[Blobrick]

Well l got the chance to try the Decoder in another loco this afternoon, with unfortunately exactly the same result. The second loco ran perfectly on DC but as soon as the Decoder was installed, dead no movement. As l suspect lightning does not strick twice in the same spot, the issue is the Decoder, so l ll speak to the supplier tomorrow. 

Many thanks to all who contributed to this thread, you help is very much appreciated. 

 

Bob C

[peterm1]

16 hours ago, Izzy said:

 

 

I find with the odd ‘fussy’ loco on a program track that it is helpful to physically hold them down to ensure proper contact. Did you try running the loco with the decoder at the default address before attempting to change it? Always a good idea to do that first with a new decoder. I do wonder if the attempt to change the address has sent a scrambled signal that the decoder read as something else and it does need a re-set. Shame your system can’t do that. 

Bob

Having seen that the problem won't be sorted out here, I'll just say that if I have a loco with clean wheels and clean programming track, that still isn't making proper contact with that programming track, I carefully put a piece of lead on top. The extra weight works well. I must get round to asking my wife to bake a beanbag weight.

[rogerzilla]

I had a new, dead Bachmann decoder this week.  Loco just made a "zzzzt" noise and the DCC controller indicated a short circuit.  Checked that the wheels were properly railed, etc, but no joy when trying again.  Loco worked fine on DC with the supplied blanking plug, both before and after the short.  Swapped a Next18 decoder in from another loco and it ran fine on DCC.

 

Sending it back for a replacement - looks as if a few bad ones do slip through quality control.

[rogerzilla]

An update on the above - Rails sent a replacement decoder and that did the same thing in the Dapol class 27 - a buzz and a short.  So I swapped decoders with the EFE Class 17 and then both locos ran perfectly.  From this I learned two things:

 

1. Zimo have slightly changed the latest MX series decoders, of which this is a rebadged one.  It has the same Bachmann model number but a visual inspection shows the PCB is very slightly different.

 

2. The Dapol 27 is fussier than the EFE 17.