[Vulcan]

Hello all,

Please excuse the barrage of questions -

After yesterday successfully installing my first ever decoder in to my Farish Voyager with a 6 pin decoder, I decided today to try my luck with a Farish 66 and solder a decoder to the PCB inside.

At first I thought it was going to be the easiest thing in the world - I followed the instructions to the letter and prior to putting the body back on, the loco ran perfectly. However, in the process of putting the body back on I must have done something, as I no longer have control over lighting in one direction. The loco runs perfectly, but one set of lights (those connected through the yellow wire I believe) are always on, even if no lighting is turned on from my Powercab.

I've checked and double checked all my soldering, to the point where I've re-done it all, but the problem persists.

Any suggestions please?

 

[upnick]

Hi James,

Glad you have got the install in all safe, have you tried pressing the headlight button several times on the cab to turn off the lights ? this can cure it.
Ask as many questions as you need to James ....... sure someone will have the answer.

 

[Vulcan]

Hi Nick - that doesn't seem to do anything, it just repeatedly turns the other set of lights on and off. I'm at a loss, everything looks good to me.

 

[Edwin]

With Farish 66s I always put a piece of Plastikard under the PCB and am very careful to route the decoder wires between the PCB components on the way to the pads. If you get a wire on top of one of the black rectangular components on the centreline of the PCB the the roof will probably bear on this when the body is reapplied. And if there is no insulation under the PCB then this can push it down so one of the soldered areas underneath comes into contact with the live chassis. Does the problem go away when you take the body off again? Do you get an error when trying to programme the decoder with the body either off or on?

Otherwise all I can suggest is check very carefully with a magnifier that there is not a tiny connection between the yellow pad and the adjacent ones. Never had this problem but I imagine a short between the yellow wire and the adjacent black wire (which is also connected to one side of the chassis) could something like this to happen.

Not directly relevant to this issue but you also need to put a bit of shrink wrap round the two motor terminals, as with time they can wear away the insulation on the chassis slots they pass through and if this happens it will probably fry the decoder.

 

[Vulcan]

Thanks for your input Edwin. I've done everything that you've suggested but the problem persists - I'm starting to wonder if there's a fault on the decoder.

Luckily, this loco is my test loco (it was damaged when I got it from eBay) and so it's not too critical that it's working perfectly. It's about to be my guinea pig for fitting some DG couplings anyway.

 

[upnick]

Hi James,
Have you set a new loco address for the 66 ? is so try a factory reset on the decoder ....... and try the loco on address 03 ......... shot in the dark but it might be worth a try.

 

[Edwin]

QUOTE (N Gauge James @ 8 Feb 2009, 15:48) <{POST_SNAPBACK}>Thanks for your input Edwin. I've done everything that you've suggested but the problem persists - I'm starting to wonder if there's a fault on the decoder.

Luckily, this loco is my test loco (it was damaged when I got it from eBay) and so it's not too critical that it's working perfectly. It's about to be my guinea pig for fitting some DG couplings anyway.

Could equally well be a fault in the loco PCB, that affects the lighting circuits only when used on DCC. To pin down the fault, try unsoldering the yellow wire from its pad and connecting a voltmeter between it and the blue wire (which you may need to unsolder as well). Power off the track when connecting the meter (croc clips probably best) and don't power up until you're sure that the meter wires aren't touching anything they shouldn't! If you get about 12 volts DC at the times when the lights should be lit, and zero volts at other times, then your decoder is probably OK. In this event it is possible to get rid of the PCB and hardwire the lights (via resistors) and wires direct to the decoder.

 

[poliss]

I found this warning about the 66 shorting out on the TCS website. http://www.tcsdcc.com/bachman_grahan_farish.htm
More info on decoder fitting here. http://www.tcsdcc.com/decoderpics/bachman_grahan_farish.htm