Hornby K1 #62064 R3243 DCC Problem

[Josh_Morrell]

So,

Back in 2016, I received a Hornby K1 (R3234) for my birthday. I recently tried to install a decoder into my K1 (hornby R8249) and when I put the loco on the track, the loco would run as if the power was at full, when the controller (bachmann EZ command) was at zero on the throttle. 

I then tried a hattons decoder, and the loco responded as normal going forward, albeit with a lot of noise, but went backwards as if the throttle was at full. This time, the loco only moved when I moved the throttle.

I then tried another hornby chip from a dcc fitted hornby mallard, and the loco acted like the first scenario, with the exception that this decoder started smoking after going around one curve.

My layout I believe is 8 x 4 and all of my other dcc fitted locos act normal and work perfectly fine. My track connections are fine and the track is cleaned regularly. 

When my K1 was put back to DC, it ran perfectly fine.

I have a feeling there is a wiring issue in the tender that is overloading the circuit or something.

Has anyone had this problem with the Hornby K1? Or perhaps with a similar locomotive?

[walkingthedog]

DCC locos taking off like a rocket is usually due to dirty track and/or wheels. 

 

I see you say the teack is clean but what about the wheels?

[Josh_Morrell]

DCC locos taking off like a rocket is usually due to dirty track and/or wheels. 

 

I see you say the teack is clean but what about the wheels?

I cleaned them too. I try to clean them on a daily basis.

[Josh_Morrell]

I read on another forum that it might be dc runaway, where the loco is "stuck" in dc mode even with the decoder and reads the signal as go at full. 

[walkingthedog]

I you need to clean on a daily basis you may have a problem, that shouldn’t be necessary. DC runaway is usually caused by dirty wheels/track.  You can disable DC running but I’m not the person to tell you how. 

[RedBill]

 Hi Josh,

 

Are you able to reset your decoders to factory default. Have you tried this yet?

Did the K1 behave normally whilst running it in on DC?

 

Bill

[Josh_Morrell]

I you need to clean on a daily basis you may have a problem, that shouldn’t be necessary. DC runaway is usually caused by dirty wheels/track.  You can disable DC running but I’m not the person to tell you how. 

 

I am probably cleaning more than I need to; I just like making sure.

[Josh_Morrell]

Hi Bill,

Not sure how to reset the decoder (unless you mean just by putting it to address 3).

I have a bachmann EZ command and that has limited functions.

 

And Yes, the K1 behaves normally on DC.

 

[Fishmanoz]

Hi Josh, yes your symptoms sound a little like DC Runaway, which is not “stuck” in DC mode rather the decoder is seeing a less than perfect DCC signal then misinterpreting it to be DC.  You can stop this by turning DC Running off at bit 2 of CV29 by subtracting 4 from the value in CV29 and writing this new value to it.

 

Imperfect DCC signals are often caused by dirt and so bad connection somewhere in the signal path, hence WTD’s very good suggestion.  However, it can also be caused by a more sensitive to signal decoder, often more likely if it has been subject to seeing shorts occurring on the track which can generate electrical spikes and sometimes cause decoders to reset.  Have you had anything like that happen, maybe this or another loco shorting over points?  So your decoder may be damaged, but do try the reset suggested by Bill by writing 8 to CV8.

 

Then a decoder smoking is also a worry.  For a start, they aren’t allowed until they are 18, and also means they are being subjected to an overload.  That and the noisy running might indicate some jamming in the drive train of the loco, so you might check that out too.  Does that decoder still appear to be working after smoking?  It’s unlikely, they’ve usually had it if they’ve reached that point.

 

Last thing, I’m not sure why you think the tender is causing the overload.  Is there something you haven’t told us leading you to that conclusion?

 

PS.  Could you please stop using the white arrow in the blue box, it is not a reply to post button.  Just use the text box at the bottom of the screen and the green Reply button, just as everyone has done replying to you.

[RedBill]

Hi Bill,

Not sure how to reset the decoder (unless you mean just by putting it to address 3).

I have a bachmann EZ command and that has limited functions.

 

And Yes, the K1 behaves normally on DC.

Hi Josh,

 

Searching Google, I note that the Bachmann EZ has no ability to reset your decoders. So setting it to address number 3 is not what I was looking for. When a decoder is reset to its manufacturers default setting it will automatically return to address number 3.

Were those decoders you fitted to the K1 bought new by yourself and have you tried them  in any other loco to see that they are functioning correctly since?.  

 

Bill

 

[96RAF]

The sooner the blue button goes the better...

...either that or the default cursor position needs to be outside the yeloow box.

[Josh_Morrell]

The reason I kept mentioning the tender is because it's one of the newer hornby locos with the tender pickups and where the dcc chip stuff is located.

Now, the only time I would have an electrical spike/short is when a loco would derail on points, but what the K1 is doing is on straight and level track.

The decoders I have been using were purchased brand new by myself from Hattons, 8-pin sockets with back EMF (I don't know the product code off hand); they were a set of 10. The other hornby chip I purchased months ago and works with other locos. The last chip (the smoking one) was from a DCC fitted Mallard (R2746X or something like that). I planned on replacing that chip anyway and just wanted to see what would happen.

Since I have the Bachmann EZ Command, I have no way of changing any CV values.

Also, the noise I mentioned was when I installed the Hattons decoder. It sounded like when you put a dc loco on dcc track, where you have no power, but it still makes noise. The hattons decoder would also get hot when I tried to run the loco. 

[RedBill]

 Hi Josh,

 

As I understand it. From what you are saying, all the decoders you have tried in the K1 work fine when fitted back into other locos. As the K1 model is relatively new, there should be no issues with the wiring. The only unknown will be the motor itself. If you have the skills to replace the motor, you may want to consider this as an option.

 

I had similar issues with a brand new Fleischmann model several years ago. I couldn't get it to run smooth and quiet. .In the end I bought and fitted a new motor that cured the problem once and for all.

 

Bill