Can program, but can't move? (Farish 37 / Zimo decoder)

[Lacathedrale]

I've got a Farish 37 with a 6-pin socket - I removed the blanking plate and inserted a Zimo MX622N. I placed onto my main track with no programming. I could select loco address 3 and dial up the throttle. Very short rhythmic pulses of movement appear - a fraction of a second every few seconds.  If I place it on the programming track, I can change the loco address (and repeat the previous exercise on the main).

 

Loco runs fine on DC.

Control station/throttle work fine with other DCC locos.

Track is clean (and was cleaned)

Wheels were grubby but were cleaned.

 

The only thing that doesn't feel perfect is that the DCC chip fit is very loose - pins on the Zimo are about 1cm but the socket on the Farish PCB is only 3-4mm.

 

This is my only 2mm DCC loco so this is actually the only loco I can test on this layout unfortunately

 

I would really appreciate any thoughts you might have!

[Lacathedrale]

Hi all,

 

After posting the above I braved my 2 degree shed again to test and I managed to resolve the issue -the connector on the Zimo is indeed too long and/or the Farish 37 socket is too short. If held positively in place (i.e. with Kapton tape) then the loco can be programmed and run. I found an N gauge loco (which obviously I can't run through my 2FS pointwork, but which is happy on plain track) and transferring the decoder directly did not work initially because it needed a good clean too, after which it also worked.

 

I hope this helps anyone else with a similar issue with this combo of decoder and loco.

[njee20]

I trim the pins on all my Zimo decoders and put a small kink in them with some pliers. Like you I’ve often found them a sloppy fit in N gauge locos.

[Graham Radish]

Tin the contacts

[Paul80]

I also always trim the pins and put a kink in them. This I find especially necessary with Dapol sockets which I find looser than Farish.

 

Don't know why Zimo use such thin wires, don't think anyone else does. But as they are such good decoders it's something I will live with and work around.

[jpendle]

I use Zimo exclusively in my N Gauge stock. I have only seen the 'loose contact' issue in a couple of locos, most have worked perfectly without any need for kinks in the wires or tape, etc, etc.

 

Now that Next18 is being used this should no longer be an issue as all manufacturers should be using the same plug/socket pair.

 

Regards,

 

John P

[Izzy]

I use Zimo exclusively in my N Gauge stock. I have only seen the 'loose contact' issue in a couple of locos, most have worked perfectly without any need for kinks in the wires or tape, etc, etc.

 

Now that Next18 is being used this should no longer be an issue as all manufacturers should be using the same plug/socket pair.

 

Regards,

 

John P

Only some new arrivals use the Next18, many are still coming with 6-pin sockets, let alone re-runs etc, so they will be around for quite a while I think. My experience is that apart from Zimo, CT, Lenz, Digitax also use small round pins. Like others I tend to put a kink in them. The main problem seems to be the variation is the sockets, with some being far looser than others.

 

Izzy

[Lacathedrale]

Yes, the GF 6-pin socket on the Type 3 is really lose, you could turn the loco on its end and shake it and I'm sure the chip would go flying. On the other hand, the socket on the GF 64xx is much tighter and firmer (oo-er)

[Graham Radish]

Zimo are defo the best out of the lot, the cv list is as long as a motorway, i tried a dcc concepts chip out of curiosity, they are not even in the same league, if you have zimo you have everything, they are superb.

 

From now on im sticking to buying zimo chips from digitrains with paul chetters sounds, especially their class 37 stuff, they are biblically good.

 

You can pick up the farish class37 stock pcbs from Bachmann for a few quid, so with this said i would solder the zimo decoder pins to the pcb itself to make it permanent and with perfect connection.

 

Whenever you handle these decoders always wear silicone gloves.

Edited January 12, 2019 by Graham Radish