Graham Farish dcc ready class 37 issues

[robgregson1]

I have recently aquired a brand new GF class 37 in blue from a well known big shop in liverpool. as per the instructions, i ran it in on dc first. very smooth and quiet. i then put a bachman 6 pin decoder into the loco and i cannot get it to move. the headcode lights are on on both ends and when i increase the power, the lights illuminate like they should (white one end, red the other) but when i change the direction, the lights stay the same and no movement at all. can anyone shed any light on this. cheers

[Edwin_m]

What happens if you put it on the track with neither the blanking plug nor the decoder inserted?

 

Do the lights actually change when you increase the power as you mentioned? They should be on steadily with DCC.

 

This may be a very silly question, but when you put the decoder in were you actually running it on on DCC or DC? Most decoders will work on DC but the Bachmann 6-pin won't.

[locoworks]

he didn't actually say the lights changed when he increased the power? just that they worked as they should.

[robgregson1]

It was on the track on it's own being powered by a dcc controller. With the speed set at zero, both B

Headcode boxes where illuminated. When I increased the speed, one headcode illuminated as it should and the red lights lit up on the other end. When I changed the direction, the lights didn't change. All the time the loco didn't move. The chip was tested in another loco and works fine. The class 37 works normally on dc.

[Edwin_m]

Thanks for confirming that. Lights changing as the motor speed changed sounded like the type of thing that only ought to happen on DC.

 

Worth checking that the decoder pins haven't shorted to anything else - sometimes they can go right through the socket. Also putting a 6-pin decoder in upside down can cause some odd problems, don't recall exactly what it does but again worth checking. Usually the decoder will only go in the right way up.

 

Otherwise it sounds like a wiring or PCB fault within the loco. This can be confirmed by putting it on the track (DCC) with no blanking plug or decoder fitted. If any of the lights illuminate there is a definite fault. Case of returning to the supplier I think.

[Nigelcliffe]

I'd start with:

 

1) decoder upside down. Its so common. If I remember correctly, the Bachmann own-brand chip has a dot next to pin-1

Wiring should be (from pin 1 to pin 6): Orange motor, Grey motor, Red track, Black track, White light, Yellow light.

 

2) check DCC controller settings. Definitely on 28 or 128 steps, and not on 14 steps ??

 

3) If not the above, get out multi-meter, remove decoder from loco and carefully check for any shorts between the track pickup pins and any others. I have found some Bachmann locos where there is a short from motor brush prongs to chassis (pickup). The loco thus runs perfectly on DC and shorts out the DCC chip. (And, unfortunately, such a short may "pfff" a Bachmann 6-pin chip).

 

 

 

 

- Nigel

 

( edit correcting typo of DCC when I meant DC...!)

[Steven B]

If the lights work directionally and can be turned on and off with F0 then it might be worthwhile checking the contacts that take the power from the PCB to the motor.

 

On one of my Class 150 Sprinters they got dislodged when I removed the blanking plug and fitted the decoder. The Class 37 may be similar.

 

I'd love to know why the pin-outs on the 6 pin decoder were chosen to be motor-motor-track-track-lights-lights. Surely it if had been motor-lights-track-track-lights-motor you'd just end up with a loco that runs the "wrong" direction if the decoder was fitted pin 1 to pin 6 rather than pin 1 to pin 1.

 

 

Happy modelling.

 

Steven B.

[robgregson1]

Problem solved. The 37 is the first graham farish plug and play loco i have got. i had taken the decoder out of a Dapol class 66 and put it into the 37 in exactly the same way. the problem is that the farish plug is inverted in relation to the Dapol one. took the decoder out and turned it over and everything works fine. it is all a learning curve. thanks for all your help. cheers rob

[Etched Pixels]

I'd love to know why the pin-outs on the 6 pin decoder were chosen to be motor-motor-track-track-lights-lights. Surely it if had been motor-lights-track-track-lights-motor you'd just end up with a loco that runs the "wrong" direction if the decoder was fitted pin 1 to pin 6 rather than pin 1 to pin 1.

 

It makes it much less likely to damage anything the lights feed back via the common so other arrangements would expose the decoder to unexpected large input voltages on the output side which tends to cause returns and smoke