Lionel Fastrack Gated Crossing Replacement Flasher Bulbs - Solved

If it is a LED, it should be one of the std sizes available almost anywhere and you could replace both.  Have you tried removing them to see how difficult it would be to replace them?

Brendan

I have not removed it yet.  My first impression is that these are glued into the sockets and will come out destroyed in pieces. 

"The Train Doctor" has a lot of replacement parts. Here's his website: http://www.thetraindoctor.com/

The manual for the 6-12062 presently on the Lionel site suggests the lamps are not user-serviceable.  That said, it makes sense you may have to destroy the LED to take it out.  Post photos and I'm sure one of us can identify a suitable replacement.  As Brendan suggests it is more than likely a commonly available and inexpensive component.  I'd expect you'd have to replace both to match brightness/color. 

It appears in your photo the 3-wire assembly has 1 black and 2 red wires.  LEDs are polarity-sensitive so need to be re-attached in the correct orientation.  

Here is a close up of what we are trying to replace.  They measure 3 mm diameter which is a common size LED used by Lionel.  It's hard to see on the flasher assembly photo above but there are actually 4 wires (2 red and 2 black) that feed up to the lights and I agree on polarity dependent. 

Have you considered that perhaps the PCB board/ light driver has failed?

Disconnect a flasher wire and test with an old worn 9 volt battery to keep the volts and amps low. test the lamps.

If it is the lamps:

here is red grain of wheat bulbs - perhaps a heat gun will loosen the bulbs from the housing. I would hot glue or only a small dab of glue for repair removal.

This is definitely a modeling project to repair this.

Thanks Carl for the question, recommendations and the link.  I was actually down to the PCB when I determined the bulb was bad.  My Fluke multimeter has a diode tester and with it's internal 9 volt battery also illuminates the LED when checking it.  I've been able to validate it's not a polarity/wiring problem.  If I am able to simply replace the bulb, solder the leads, and heat shrink in place this won't be too bad.  If I have to run the leads through the gate assembly to underneath it's going to be a challenge. 

Good troubleshooting - I would assume it is a series 2 then - you know- looking at the black lens hoods - they almost look like the  holders made for indicator LED - will that pry off of the front ? - as in it is not even glued - agree that they are the 3mm LED then

I would still put a hair dryer or heat on there to warm stuff up and pry around - what does the back look like? small holes for wires only? - that would confirm that it would have to come out the front

You can see 2 wires and heat shrink on the back of the fixture that exit a hole before running down inside the post.  I will provide a pic from that side later today.  

I know series one is bulbs. Then I guess series 2 is LED's. Either way it is going to be a complex repair. Good luck!!

Lionel is listing the same part for both Series 1 and 2.   It is described as bulb.  I am starting to wonder if these are incandescent bulbs or LEDs.  

Steims posted:

...

My Fluke multimeter has a diode tester and with it's internal 9 volt battery also illuminates the LED when checking it.

What voltage did the meter read when the LED lit up in diode-test mode?

The diode-test mode injects a small test current of, say, 1 mA and then measures the voltage across the diode.  1 mA would illuminate an LED but I can't imagine it lighting up a 14V 50 mA grain-of-wheat incandescent bulb if that's what is used in the non-LED version.

Not too suggest sacrilege but maybe it is better to just replace the whole cross buck with something like this if getting a bulb replaced is impossible.

Brendan

I will keep that open as an option Brenden.  I attached a pic from the back view.  I recorded the diode forward-biased voltage readings. 

Working LED read 1.745 volts. 

Failed LED read 0.002 volts.  

These act and perform as LEDs.  No more wondering if these are incandescent bulbs.

Steims posted:

… Working LED read 1.745 volts. 

Right.  So if the diode-test current was 1 mA (as Fluke and others use), that's a whopping power of less than 2 milliwatts (1.7V x 1mA).  It would take quite the imagination, or stunningly good eye-sight, to see 2 milliwatts even faintly illuminating a 700 milliwatt (14V x 50mA) incandescent filament bulb!  

As for the "we_honest" signal, they have been known to use the "common-anode" configuration whereby the 2 "+" wires are tied together.  In your earlier photo, it appears Lionel tied the 2 black wires together suggesting a common cathode configuration (assuming black is "-", red is "+").  So you wouldn't be able to use the existing Lionel circuit (presumably common-cathode).  In any case, since 3mm red LEDs go for about a penny a piece...and you've come this far...I think it would help the OGR community to go the distance and repair your LED-based crossing signal.  In my opinion of course.

Separately, if someone stumbles across this thread in the future, I'd think it would be fairly simple to convert the original incandescent version to the LED version.  So if an incandescent version goes out, and you don't want to send the unit back to Lionel as suggested in the manual, consider converting to 1-cent red 3mm LEDs.  I'm guessing the incandescent bulb is/was a 1/8" grain of wheat which is effectively the same size as a 3mm LED (1/8" = 3.2mm).  Some soldering and such will be involved but I think a 5-cent resistor on the common black wire going to the signal head is all you'd need to add to reduce the ~14V (or whatever your accessory power) down to the ~2V needed by the red LEDs.

I just measured at the PCB and the board is cycling 5VDC to each pair of red LEDs (one on each crossbuck).  

So clearly we're not driving 14V bulbs!

Do you have a plan on removing the broken LED? I think it will good for the record to document what it takes to loosen the glue or whatever.

I'm going after this repair.  I will keep the thread up to date as we continue this project. 

stan2004 posted:

As for the "we_honest" signal, they have been known to use the "common-anode" configuration

 

Good to know. 

Brendan

Well this may not be very satisfying to those interested in the gory mess I was about to undertake but got lucky and will chalk up a win.  I took a small flat blade screwdriver and I pried it lightly between the heat shrink anode and cathode of the offending LED.  I hit it then with my meter and it worked.   Looks like the metal anode and cathode leads on the back of the LED were shorted inside the fixture/flasher socket out of view. 

If an LED ever does need replacement this will take extreme patience, steady hands, and excellent vision to pull this off.  I hope it won't have to be me.

Thanks for the ideas, questions, and support.     

we were hoping for the dissection DIY - but, I am glad it was a simple fix. You have signals again!