Last week I received three new Athearn Genesis GP38-2's in BN colors. They come with a rotary beacon on the cab. On one of them the flashing LED is barely visible compared to the other two. Using JMRI I changed it from a rotary beacon to a strobe, thinking that might fix it. It didn't. Then I noticed under each FX lighting tab there is a setting for bulb type, incandescent or LED. The two good engines were set for LED, the faint one for incandescent, so I changed that to LED but it made no difference. Any thoughts on what the issue is and how I might fix it? I could understand if the LED didn't light at all, but I don't get that it's faint. Thnx all.
Without analyzing further: if you can exchange this locomotive cheaply, I would do so.
I'd think 'incandescent' would send much more power to a light source than 'LED'; the fact that the light doesn't change brightness tells me the decoder -- I am assuming you are changing data in JMRI on a decoder and getting confirmation -- is not changing voltage between 'incandescent' and 'LED' and the "fault" causing the dimness is in the LED or too much resistance if some kind in series with it.
A quick check would be to do the 'coin cell' check across the physical LED connections to see if it comes up bright. Is it possible that the LED is dislodged or not positioned correctly?
I would also take quality control into account. Possibly the LED has shifted slightly in the shell and isn't aligning with the exterior beacon as it should.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Overmod A quick check would be to do the 'coin cell' check across the physical LED connections to see if it comes up bright. Is it possible that the LED is dislodged or not positioned correctly?
DO NOT apply any kind of power to the LED while it is attached to the decoder. The input external voltage could potentially damage the decoder.
Mark R.DO NOT apply any kind of power to the LED while it is attached to the decoder. The input external voltage could potentially damage the decoder.
That said: on general principles alone I'd agree that if you can unplug the LED or string in question to test it isolated, do so as he recommended.
Thnx for the info and suggestions. Because of my lack of finger dexterity I'm reluctant to try to open up the shell. I'll try a decoder reset (don't know why I haven't done it already!) but I doubt that will do anything. I didn't purchased these because they come with this feature so I can live without it. Or I might contact the vendor to return to them or Athearn. It's just annoying
Th eonly thing usually (USUALLY) safe for LEDs is a 3V coin cell. The reason not to use alkaline? They have a low enough internal resistance that they can deliver a very high amount of current. The typical coin cell cannot.
The difference between an LED and Incandescent setting in a decoder has to do with the persistence of an icnadescent filament. An LED is pretty instantaneous - cut the power and it's dark. An incandescent bulb glows for a bit as it goes off. So the decoder has to adjust the rate of change accordingly to get the same sort of effect witht he two light sources.
But I would tend to agree with Mark, most likely the LED is somewhat askew in the beacon housing and thus the brightest part is not shining through like ont he other two.
There's an off chance of a factory screw up, putting a 10K resistor in place of a 1K. That would make for a rather dim LED as well. 102, 103 - it's all the same (102 on a surface mount resistor means 10 with 2 zeroes, aka 1000 or 1K, 103 is 10000 or 10K)
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
kenny dorhamSorry if i missed it, but.......they are new units and you just got them, why not just send it back.?
I agree.
Could be a bad LED, I’ve run into LEDs that are just dim. Can you check the voltage at the LED?Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
RR_MelCan you check the voltage at the LED?
Overmod RR_Mel Can you check the voltage at the LED? The problem is that, in a message roughly crossing with my suggestion to test with a coin cell, he said he wasn't comfortable even with the idea of taking the shell off. I can't think of any practical way to test, including even physically inspecting the LED alignment, without doing so -- so his only real recourse is to return it either for replacement or service, and I again recommend the former to him if he is still mulling over how to proceed.
RR_Mel Can you check the voltage at the LED?
The problem is that, in a message roughly crossing with my suggestion to test with a coin cell, he said he wasn't comfortable even with the idea of taking the shell off. I can't think of any practical way to test, including even physically inspecting the LED alignment, without doing so -- so his only real recourse is to return it either for replacement or service, and I again recommend the former to him if he is still mulling over how to proceed.
I agree with you. If he isn’t going to remove the shell, he needs to send it back. He has done everything that can be done without removing the shell.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Holy Cow...... (rr_mel) the railroad info on your site is awesome.!
The quick story of the SP Guys letting you ride the train as a young, high school, guy was a fun read. THAT is something that will not be happening anymore :-)
Somewhere around 1990 when my grandson was about 6 yrs old his buddy’s dad was an engineer for the Santa Fe and he gave me a ride in what I think was a Dash 8 from Bakersfield to Tehachapi up the Loop. Great ride but slow going. My wife had to wait at Tehachapi for an hour and she had a long drive.The memories from my steam rides were much better than the long slow up hill in the Cab of the diesel, but it was air conditioned. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Thnx Kenny, Mel. That's exactly what I ended up doing. Very easy transaction with Train World, just that I'm out another $15 for shipping it back. No biggie. A prospective problem, however, might be that on the web site this road number is no longer available. Normally I'd say just send a different one but I ordered the other three as well.
TophiasBecause of my lack of finger dexterity I'm reluctant to try to open up the shell.
I don't blame you there! I've opened up a few recent Genesis locos with lighting effects and there is a pretty good wad of wiring in there that can not easily be disconnected.
Some of the recent Genesis engines use a bronze finger contact so at least the shell can be lifted away without the tangle of wire still connected.
My Rapido, Amtrak, F40PHs have anemic roof strobes, too. Some of the "gumball" type beacons weren't all that bright but the Amtrak strobes definitely were.
On another pair of Kato F40s I wired incandescent 1.5v microbulbs (before there were any SMD LEDs) and they made a nice alternating double-pulse flash. Just right
The Burlington and later B-N sometimes used a beacon that was simply four spot lights that would alternately flash, not really a "rotary" beacon. Once the outer, amber housing got dirty and if you weren't looking directly into the cone of light you really didn't notice it .
http://www.trainweb.org/gyra/photo/pm8911_.htm
Regards, Ed
The original BN beacons were old school revolving "bubblebum machine" lights made by Federal Signal. But the motor "noise" interfered with the early EOT reception as the antennas are right up on the cab roof as well. So in came the Prime sequential beacon, early models were taller with a cast alum base and hose clamps that heald the 75vt flood lamps to the base cradles. Later models have a spun alum base with rubber housings to hold the lamps. The early design uses solid state but analog circuitry and the later version is digital. The digital ones will operate on 12vt and flash if you swap out the lamps. The early ones require 74vdc to flash. I have examples of both in my collection, both off BN units. Once the amber domes got all sooted up from the diesel exhaust, they did become very hard to see unless you were at the right angle and out of the main headlight beam. The era of the BN just prior to removal of the beacons is my favorite one.
early model 8901, off a BN U33C
Prime 8911, removed from BN GP10 #1410 by myself
Silly NT's, I have Asperger's Syndrome
Youtube link to that 8911 flashing on 12volts. original RR bulbs were 88 watts, these are 36 watt halogen for outdoor landscape lights.
https://www.youtube.com/watch?v=Q6zF7r0JJqI