Bachmann Class 150 DCC Fault

[VXDH92]

Hi everyone,

 

I have a Bachmann Class 150 that I have recently fitted with a 21 pin Bachmann decoder. The other day, the unit just stopped working, but the lights remained. When I went to try again today, the unit would move but would only travel at max speed as soon as you turned the controller on even slightly. I've tried swapping the decoder to another loco and it causes the same problem, so I guess the decoder is knackered (frustrating as it's brand new!). 

 

Even worse, I then tried another new Bachmann 21 pin decoder in the class 150, and that won't even register. I then used that new decoder in another loco and it was fine, so I'm worried the class 150 is knackered too.

 

Anyone had an issue like this?

 

Dave H.

[johnb]

First thing to try is a decoder reset. It's usually to set CV 8 to 8, but read the leaflet that came with the decoder. That returns the decoder to factory settings allowing you to reprogramme it again.

 

Has the unit been on the track when a short circuit occurred? That can sometimes confuse the decoder to the extent that a reset is the only way to clear it up. That's happened to me.

 

The second issue is something else obviously, but do check that the pins that the decoder plugs to are all straight, they are all too easy to bend (Guess how I know that!)

[VXDH92]

Thanks for that. The pins are definitely fine so I'll try the reset.

 

Dave H.

[SRman]

Some time back I had a brand new class 150 in First Great Western livery, which ran fine on test on DC, but had all sorts of lighting and behavioural anomalies on DCC.

After much testing and fiddling around with different decoders and testing the decoders in other locomotives (as you did too), I eventually traced it to a small bit of solder bridging the connections between the main PCB and the daughter board that carried the decoder - the short was between pins/tracks 10 and 11 (edit: or was it 9 and 10? - too long ago now!). Once I had cleaned the solder bridge out, the unit worked and behaved perfectly after that.

I'm not saying you have the same problem, but it could be worth checking the tracks closely under a strong light with good magnification.

Edited October 21, 2017 by SRman

[Butler Henderson]

Fault Finding Golden Rule - Work backwards from the motor - remove the decoder , apply dc direct to the motor terminals.

[petertg]

I had a problem with a Bachmann 150 and the 21 pin decoder in that, after changing the address, after a while it spontaneously reset itself to the default address. I left it at that and have had no further problem with the decoder.

[SRman]

I had a problem with a Bachmann 150 and the 21 pin decoder in that, after changing the address, after a while it spontaneously reset itself to the default address. I left it at that and have had no further problem with the decoder.

 

That wouldn't have been a Bachmann decoder, by any chance, Peter? I had the same problem with Bachmann 36-554 decoders (yes, I tried more than one out), but changing to Lenz fixed the problem.