Curious DCC issue

[nah00]

I have a pair of Intermountain SD40-2s I fit with Digitrax DN166I3 decoders. After a bit of adjustment on the motor contacts I was able to get both locos running...but now I have two problems (one self created. Self created one first: somewhere along the line my idiot self managed to snap the LED off of one of the boards. Does Digitrax cover this under warranty or is this a fix I can do myself? Not great at soldering and don't even know where I'd get the tiny LED from.  

The second one is just bizarre. The loco runs fine on DC with the DCC board in, throttle will recognize it (both the Digitrax throttle and WiThrottle on my phone) but only thing that happens is the read light comes on. No motor function at all and I can't shut off the light or change direction. I don't have any CVs programmed aside from the loco number so I'm thinking just reset the board and start from scratch? I doubt the board is fried, no scorch marks and it will still run the locomotive under DC.

Any help is appreciated. Also the new Kato Aichi DD-51 runs great with a decoder, you do have to take the light pipes on one side to fit the board and also trim a bit from the other end but no major surgery required. 

[Kiha66]

Regarding the led, digitrax has a "no worries warranty" so if you have your receipt and it's been less than a year you open a repair ticket and they give you and address to send the decoder to, then they will send you a new one for free.

 

Resetting board is always a good bet when something odd is going on, just set cv8 to 8 and it will clear itself.  If the issue persists then you'll have to check if it's physical problem or an issue you need to send the decoder in for.

Edited July 23, 2018 by Kiha66

[gavino200]

11 hours ago, nah00 said:

or is this a fix I can do myself? Not great at soldering and don't even know where I'd get the tiny LED from.  

 

It can be done but it's extremely difficult. Even with magnification it's hard. Try Kiha's suggestion.

 

 

But if you ever do try it, a low heat iron is helpful. I've never bought LEDs that small. You're talking about the teeny tiny rectangular ones - not the clear domes, right?. I've just soldered back on, ones that have come off. But... if you're going to try this, and there's space, you can buy this kind of LED with wires already attached from ebay. Cut the wires very short and solder them onto the board. It's easier than soldering directly to the tiny LED, and the're no chance of damaging the LED. 

 

If by chance you mean one of those clear plastic dome type LEDs, then try it. They're not so tough to solder. 

[Kiha66]

1 hour ago, gavino200 said:

 

It can be done but it's extremely difficult. Even with magnification it's hard. Try Kiha's suggestion.

 

 

But if you ever do try it, a low heat iron is helpful. I've never bought LEDs that small. You're talking about the teeny tiny rectangular ones - not the clear domes, right?. I've just soldered back on, ones that have come off. But... if you're going to try this, and there's space, you can buy this kind of LED with wires already attached from ebay. Cut the wires very short and solder them onto the board. It's easier than soldering directly to the tiny LED, and the're no chance of damaging the LED. 

 

If by chance you mean one of those clear plastic dome type LEDs, then try it. They're not so tough to solder. 

 

I'd actually recommend a higher heat soldering iron.  It many seem counter intuitive, but the higher temperature means that the element you are trying to heat will reach temperature faster, while the heat has lest time to spread and affect other components.  If you do soldering regularly, I'd really recommend getting something like this, it gives you a lot of control and makes tough jobs like this much easier.

[gavino200]

51 minutes ago, Kiha66 said:

 

I'd actually recommend a higher heat soldering iron.  It many seem counter intuitive, but the higher temperature means that the element you are trying to heat will reach temperature faster, while the heat has lest time to spread and affect other components. 

 

That's interesting. I never would have thought that. I have a super small 25 watt that I use for these things. I'll try your advice. Thanks

 

51 minutes ago, Kiha66 said:

 

If you do soldering regularly, I'd really recommend getting something like this, it gives you a lot of control and makes tough jobs like this much easier.

 

I actually did just buy one of those about a week ago. I haven't even used it yet. My 20 year old cheapo 30 Watt has gotten just too beat up. 

 

So, what do you use the low setting for? I'm all turned upside down now!

[Kiha66]

4 minutes ago, gavino200 said:

I actually did just buy one of those about a week ago. I haven't even used it yet. My 20 year old cheapo 30 Watt has gotten just too beat up. 

 

So, what do you use the low setting for? I'm all turned upside down now!

 

I bought mine for the same reason, and I've never looked back.  Usually I use 600 to 700 F for most components, I can turn it down for when doing work which isn't board mounted (ie soldering wire to wire), but usually I dont bother unless the insulation of a wire is melting too quickly.  

[gavino200]

Speak of the devil. I had to deal with this issue this evening. I got an NGDCC lightboard replacement decoder for my EF-65. The decoder is perfect but it comes without LEDs. So I had to try to transplant them from the old light board. 

 

I succeed with one although I beat the LED up a bit. It still worked. I fried the other. I used my new adjustable soldering iron set to the highest setting. I need to buy small tips for it though as the tip it comes with is giant in this situation. 

 

I also need to buy delicate non metal forceps/tweezers. I used my favorite pair, which are metal and they crushed the LED. A problem with this task is that you have to undo the solder on both sides. The LED doesn't want to move until both sides are unsoldered. There's no good way to get them both. I tried to do that by applying heat to the etched wires leading to the LED to get them to both melt at once. That sort of works, but you cook the board and it smells horrible.

 

Perhaps next time I'd removed the LED from the board without heat by undercutting it with a blade.

 

In any case I had to use another small LED that is similar but a tiny bit to bright. 

 

I'm going to see if I can find a source for this kind of LED to make things easier in future. I'll post here if I find out what they are.

[Kiha66]

I am very interested in these conversions, as I have a few kato locos and DMU's I would like to convert using his decoders.  The requirement to use the old headlights was worrying to me, perhaps someone  can email him and ask what LEDs he would recommend?  How much did it cost to ship the decoders?   Perhaps at some point we can do a group order when a bunch of members are planing to convert at once to save on shipping, as well as to acquire a bulk amount of the side view LEDs necessary.

[gavino200]

4 minutes ago, Kiha66 said:

I am very interested in these conversions, as I have a few kato locos and DMU's I would like to convert using his decoders.  The requirement to use the old headlights was worrying to me, perhaps someone  can email him and ask what LEDs he would recommend?  How much did it cost to ship the decoders?   Perhaps at some point we can do a group order when a bunch of members are planing to convert at once to save on shipping, as well as to acquire a bulk amount of the side view LEDs necessary.

 

Shipping was (only?) 800 Yen. The decoder cost 4200 Yen. It was a perfect fit. Very slick. The stock LED fit very well. So did the replacement I used, which was one of these (below) laid on it's side with the wires cut back to around 2mm. This LED was brighter than the stock LED and a harsher white. I may replace it later.

 

https://www.ebay.com/itm/20Pcs-T1206WM-Pre-soldered-Micro-Litz-Wired-Leads-Warm-White-SMD-Led-1206/273130478798?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2648

 

Interestingly these NGDCC decoders have the ability to wire in extra LEDs for read rear lights. 

 

Group buys are difficult to organize, but I might be interested. I'll have to look at his stock to see what I'm likely to use.

 

 

[chadbag]

I want some of the dual polarity function decoders so if someone gets a group buy together I'll be in.

 

[gavino200]

6 hours ago, chadbag said:

I want some of the dual polarity function decoders so if someone gets a group buy together I'll be in.

 

What’s a duel polarity decoder?

[kvp]

1 hour ago, gavino200 said:

What’s a duel polarity decoder?

One that changes the polarity of the two function outputs depending on the direction, very much how analog mode operates (ground-power and power-ground). Normal decoders have a common supply and two low active function wires (blue-power, white-ground1, yellow-ground2) Using a polarity changing function decoder avoids the rewiring of white/red headlight circuits.

[gavino200]

10 hours ago, kvp said:

One that changes the polarity of the two function outputs depending on the direction, very much how analog mode operates (ground-power and power-ground). Normal decoders have a common supply and two low active function wires (blue-power, white-ground1, yellow-ground2) Using a polarity changing function decoder avoids the rewiring of white/red headlight circuits.

 

That's great. I'd buy a bunch of these. Anything to streamline the chore of DCC conversion! It would be nice to have a couple of these for when the Hello Kitty train arrives. 

[chadbag]

I think this is it (only one with bipolar in the description of the function decoders listed):

 

http://www.snjpn.com/ngdcc/extFx/extFx4bpj.htm

 

@kvp or someone with experience will be better able to explain.   

[kvp]

6 hours ago, chadbag said:

I think this is it (only one with bipolar in the description of the function decoders listed):

 

http://www.snjpn.com/ngdcc/extFx/extFx4bpj.htm

 

@kvp or someone with experience will be better able to explain.   

Sadly this is a sushi function extender, not a full decoder as it requires a main decoder to supply DC power and the decoded signals.

 

Usually a rare few motor decoders have the option to drive a bipolar headlight assembly through the main motor outputs by switching to bipolar headlight mode. (essentially decoding F0 and direction for the motor driver instead of speed and direction) 

[chadbag]

27 minutes ago, kvp said:

Sadly this is a sushi function extender, not a full decoder as it requires a main decoder to supply DC power and the decoded signals.

 

Usually a rare few motor decoders have the option to drive a bipolar headlight assembly through the main motor outputs by switching to bipolar headlight mode. (essentially decoding F0 and direction for the motor driver instead of speed and direction) 

 

I had the wrong one.  Someone else in another thread had posted a link to one and I had landed on the wrong one but I believe this is a full function decoder and bipolar:

 

http://www.snjpn.com/ngdcc/df19/df19x4bpss.htm

 

ETA:  This one also mentions bipolar and seems to be a full function decode (only 2 functions):  http://www.snjpn.com/ngdcc/df11/df11r5j.htm

 

Edited August 4, 2018 by chadbag

[kvp]

51 minutes ago, chadbag said:

 

I had the wrong one.  Someone else in another thread had posted a link to one and I had landed on the wrong one but I believe this is a full function decoder and bipolar:

 

http://www.snjpn.com/ngdcc/df19/df19x4bpss.htm

 

ETA:  This one also mentions bipolar and seems to be a full function decode (only 2 functions):  http://www.snjpn.com/ngdcc/df11/df11r5j.htm

 

Yes, both look good. They even have a reverse direction jumper for the tail end cab car, so you don't have to mess with prgramming cv-s. The first is bipolar F0 and standard F1, F2, while the smaller one is just bipolar F0, perfect for a straight 2+2 wire install. They also seem to have an external capacitor option.

[chadbag]

7 hours ago, kvp said:

Yes, both look good. They even have a reverse direction jumper for the tail end cab car, so you don't have to mess with prgramming cv-s. The first is bipolar F0 and standard F1, F2, while the smaller one is just bipolar F0, perfect for a straight 2+2 wire install. They also seem to have an external capacitor option.

 

The only problem is the smaller one is more expensive...

 

Thanks.  I knew I had seen the right one on there 😉

[gavino200]

15 minutes ago, chadbag said:

 

The only problem is the smaller one is more expensive...

 

 

The prices seem decent. 1850 yen. Are we looking at the same decoder?

 

http://www.snjpn.com/ngdcc/df11/df11r5j.htm

[chadbag]

11 minutes ago, gavino200 said:

 

The prices seem decent. 1850 yen. Are we looking at the same decoder?

 

http://www.snjpn.com/ngdcc/df11/df11r5j.htm

 

Yes.  If you notice the other one I listed, the larger one, is only 1800 yen... 🙂

[gavino200]

57 minutes ago, chadbag said:

 

Yes.  If you notice the other one I listed, the larger one, is only 1800 yen... 🙂

 

Ah yes. Completely missed the joke. 

[chadbag]

1 hour ago, gavino200 said:

 

Ah yes. Completely missed the joke. 

 

Joke?  Rather a lamentation...

 

🙂

 

 

I'll probably buy a few of each to put in my collection so as I find I need one I have them.   Heaven only knows I'll need them (and more).

 

[kvp]

28 minutes ago, chadbag said:

Joke?  Rather a lamentation...

🙂

I'll probably buy a few of each to put in my collection so as I find I need one I have them.   Heaven only knows I'll need them (and more).

Imho the smaller one has a better chance of fitting into an N scale cab car.

 

The anatomy of them is interesting. The small one has a PIC12F1840 8 pin microcontroller, with 5 i/o pins, 1 input only pin and the two power pins. This means it can supply up to 5 outputs, but has the config jumpers, so it has 4 outputs and 2 inputs (DCC signal and config). PICs are standard for Digitrax decoders too and the decoders seem to support the common US effect features. There is a full bridge rectifier, two half H drivers and imho a zener for mcu voltage regulation (with some caps and resistors). The larger one is probaby double sided as the displayed side doesn't have an mcu, but it does have one dual transistor chip more, which probably drives the F1 and F2 outputs as standard low active outputs. The prices are pretty much the same, but the larger one is around double the thickness and the width is also slightly larger. It makes it just a bit too wide to install into many N scale trains. Both seems to be great for japanese non DCC ready models, with imho the larger one better suited for H0.