I’m reparing the headlghts on my Proto S1. Im using a 3mm LED and a 1K resistor.
Is there any reason why I can’t file the LED down a bit to fit?
The blue wire goes to the longer lead. right?
The yellow and blue wires are missing from the back-up light. What number connector on the socket do I attatch the yellow lead?
SEE CRAZY BELOW
Chip,
You should be able to but it isn’t necessary. I used black heat shrink to concentrate the beam through the headlight lense.
Yes - Blue wire (+) goes to the anode (longer). The 1K resistor can be soldered inline to EITHER pin; anode or cathode - doesn’t matter. The important thing is that it’s solder onto one of them.
Blue - #7, Yellow - #2
Tom
Thanks.
The back light works, but it doesn’t seem to go anywhere–doesn’t light the cab, just sort of shines inside the body.
It’s the front lignt that is getting to me. I doesn’t work unless I touch it on the anode side. It can be with my finger. It can be with a probe. I thought it might be the solder joint, but they all check out. if I touch the contact on the socket, it will light. It lights with DC.
But put it on the track, it will not light unless you touch it.
Is there some reason why I shouldn’t be going crazy?
Anybody?
Chip
A bad LED maybe???
JIM
I don’t understand enough how LEDs work, so ti could be. But when I touched the contacts, on the decoder side of the socket with DC leads it worked. With DCC power, it’s like it needs to be grounded.
It doesn’t really sound like a “bad” LED. They usually work or they don’t. [:)]
I wish I was more familiar with the engine, but it sounds like a polarity/wiring issue. You seem to be completing the circuit by touching the LED, but I’m just not sure what’s going on.
When you say the light works on DC but not DCC, are you actually moving the engine directy from a DC track (where it works) to a DCC track (where it doesn’t?)
I’m not doubting you, just trying to get a handle on your troubleshooting method. Finding electrical problems are tough and it involves isolating each element and finally narrowing it down to the problem.
If I were tackling this, I’d verify that the LED works on a DC track, in forward and reverse (I assume it’s wired directionally.) Then immediately move it to the DCC track and see if it works in analog mode. Forward and reverse.
Then in DCC mode. Forward and reverse.
Then I’d put a regular bulb back in and repeat the above. If it works fine with the bulb but not the LED, then it should be a polarity/wiring issue.
Mike Tennent
I don’t have a DC track.
What I did was pull the decoder then insert DC powered probes into the the DCC socket where blue and yellow lead are attatched. The LED lights.
Put the decoder back, set it on the track, and it only works if I touch the anode side with a tool or my finger. The lightest touch is enough to light it. This can be near the LED, on the solder joint or on the socket.–as long as I touch the anode side somehwhere.
So what’s my next step? Try another LED?
Chip,
Did you check for any cold solder joints? They are notorious for causing these kinds of problems. Be sure that all your joints are nice and shiney. If there is one that is dull in appearance, that may be the culprit. Add a wee bit of flux to the joint and reheat. Also, check for a good solder joint between your anode and resistor.
You can also test the LED directly with a 9V battery, but the LED has to have the resistor solder inline or it will go poof.
Tom
I don’t think that’s telling you anything except the LED is good. It doesn’t say the decoder is powering the LED correctly.
What you need to do is get back to a known working point and start again from there. I’d suggest desoldering the LED and replace it with a bulb and verify that that works.
If it does, then you know the decoder is powering something. Next re-install the LED, but use some surplus/excess wire that you can cut. Wire the LED as before and test. Don’t hold it while you’re testing.
If it doesn’t work, reverse the wiring and see if that works.
If that fails, try another LED.
Hope this helps,
Mike Tennent
The headlight connects to the WHITE and BLUE wires; the rear light to the YELLOW and BLUE. Blue is the common for both headlight and backup light.
If you intend to use directioinal lighting where only one LED is on at any one time, you need only one resistor provided you put it in the blue lead.
I resoldered every joint and test it with the transformer all the way back at the socket. IT worked from that point.
cacole,
Is the Blue wire common negative or positive? That might explain things.
Sorry about my unfamiliarity with the decoder. I haven’t fooled with one for quite a while.
Mike Tennent
It tells me that the solder joints are good and that the LED will light with 14v.
I have some 12v lights about the same size as a grain of rice. I have 240 ohm and 1K resistors. Frankly I don’t care if I use a light or LED.
I know that because if I touch the anode, the LED will light.
Mike,
The Blue or common wire is (+) and is attached to the anode (longer) pin on the LED.
Tom
The socket is in between the two lights and on almost on top of the rear light. And you’re right, it is the rear that is the problem not the front. The front LED works fine, if not a little dim.
The blue wire is the PLUS (+) side in accordance with NMRA standards and recommended practices.
Man, I’m scratching my head on this one. [:)]
OK, the front LED works, right? So take it out and use it for the rear light. You know it works, so if it doesn’t work in the rear, you’ll know it’s not the LED.
Mike Tennent