DCC HO GP-40 #60301 - Decoder not working?

[Kimble]

Hi,

I have a Bachmann model # 60301 HO GP-40 "dcc equiped" loco that I bought at a show.

On the programming track I can read or set any CV, change the address and even reset to the default decoder settings. On the mainline - zip! No lights, no movement.

It does run on DC.

Any ideas? I don't think the decoder is bad, as I can read/write to it.

R Carignan
Maine

[rustyrails]

I don't know what sort of DCC system you have, but my Digitrax requires me to push a button to turn on track power.  Check the documentation that came with your system.  Hope this helps.

Rusty

[Guilford Guy]

Assuming you have the track power on, it's possible the motor leads are broken which would result in a functioning programming, but no movement. This doesn't explain the no lights.

[Jim Banner]

Running on dc precludes any broken wires between decoder and motor, also a faulty motor etc.

What brand of decoder is it?  Some decoders do not use CV8 for a system reset.  Others do not even support reset.

Assuming you were able to reset the decoder, did you try running it on address 3 right away or did you attempt some other programming first?

Can you tell us what values are in CV01, CV19 and CV29?  These will tell us to what address and/or what type of address the decoder is set. 

Can you tell us what values are in CV02, CV03, CV04, CV05 and CV06?  These all affect how the motor will run, including whether it will run at all.

If you cannot tell what decoder you have, ten what are the values in CV07 and CV08?  These usually tell who manufactured the decoder and what series or type it is.

What DCC system are you using for reading out the CVs?  Are you using the same one when you try to run the locomotive?  What number of speed steps are you trying it run at?

If I had your locomotive sitting on my test bench, these are the things I would be trying to determine in order to decide whether the decoder was bad or was just incorrectly programmed.

Jim

[Guilford Guy]

Oops, I overlooked that.
I'm assuming from the post that its a stock, DCC equipped Bachmann GP40, which IIRC has a lenz designed decoder.

[Jim Banner]

Alex, you are probably right about the decoder.  I just thought that since he bought it at a show, it might have been reworked.  I hate to say this, but more likely is that the seller sold it because he could not get it to work either.

Jim

[Kimble]

Thanks for all the replies.
Did I mention the lights don't work? (F0)

I brought the loco to my LHC to buy a new decoder. After chastising me for buying something at a show he said to try for an answer here. He didn't want to sell me a new decoder (which i was ready to buy) until I had exhausted other avenues.

Jim,
> What brand decoder is it?
Not sure. All the box and documentation says it's an EZ Command. I *think* it's some type of Lenz decoder, but I can't tell which one.

It's a long skinny decoder with two sets of red/black power pickup wired - a pair on each end.
Here are the CVs:
CV1 = 3
CV2 = 10
CV3 = 1
CV4 = 1
CV5 = 255
CV6 = 1
CV7 = 46
CV8 = 101  (101 I found listed = Bachmann)
CV9  = 255
CV19  = 0
CV29  = 6

>What DCC system are you using for reading out the CVs?
I have a LENZ.

I found a Bachmann decoder CV list at:
http://www.bachmanntrains.com/home-usa/ez_content/1_Amp_Decoder_Instr.pdf
and
http://www.bachmann.co.uk/pdfs/DCC_onboard.pdf

and a CV29 calculator at:
http://www.2mm.org.uk/articles/cv29%20calculator.htm

The default CV29 is "6", meaning 28/128 speed steps and DCC/DC operation.

I played with the CV29 values, but no motion on the main.

Setting CV8 to "33" will reset the decoder. I changed some CVs, set CV8 to "33" and it reset to the defaults.

Oh! I set one more test. I set CV29 to DCC only and it wouldn't run on DC. Setting CV29 back to the default (both)  let it run on DC just fine.


Rob Carignan
Maine

[Jim Banner]

Rob, let's start off by looking what those decoder values mean:
CV1 = 3      address = 3
CV2 = 10    start voltage = 12 x 10/255 = about .5 volts
CV3 = 1      acceleration rate is fast
CV4 = 1      deceleration rate is fast
CV5 = 255  full speed = maximum or CV not implemented
CV6 = 1      value of 1 indicates this CV is not used to calculate speed
CV7 = 46    series 46
CV8 = 101  (101 I found listed = Bachmann)
CV9  = 255  motor pulse = maximum width or CV9 not implemented
CV19  = 0    decoder is not set to advance consist address
CV29  = 6    decoder set for DCC/dc and 28/128 speed steps

Everything looks good to run on address 3 using 28 or 128 speed steps.  This leaves only two possibilities that I can think of - either your command station is not set to 28 or 128 speed steps or the decoder has closed up shop and quit taking orders.  It is not very common to see a decoder that can run one part of its programming but not another part.  But it is possible.  The part of its programming that allows it to accept new values for CVs seems to be working fine but somewhere in the part of the program that interprets what to do with them, something may have failed. 

I have been assuming that you run other locomotives on 28 or 128 speeds steps, but you might want to check by reading back CV29 in one or more of them.  As I see it, that is the only thing, other than a bad decoder, that could be keeping your locomotive from running.  If this were the only DCC locomotive you had and were running it on a layout that had not run DCC locomotives before, then there would be other things to check out.  Incidentally, many decoders have problems with the headlights if the number of speed steps is incorrect, so this might be a sign of that too.

Jim