DCC LED problems with an Atlas GP-7

[CSX Robert]

cacole

All decoders that comply with the NMRA DCC Standards and Recommended Practices use CV 49 for the headlight and CV 50 for the rear light...

Sorry, but that simply is not true. CV49 and CV50 is in the range of "Manufacturer Unique" CV's and are used differently by different manufacturers.

[cacole]

 All decoders that comply with the NMRA DCC Standards and Recommended Practices use CV 49 for the headlight and CV 50 for the rear light. 

Assuming that you have the rear light connected to the yellow output wire, setting CV 50 to 00 should make it directional; a value of 08 would make it Rule 17 (dimmable).

[cmarchan]

Meyblc

I'm hoping that some of the wiser & smarter DCC guys and gals can help me out here.

I have converted an older Atlas GP-7 "classic" from Dc to DCC and installed LED's with the resisters. I have done this to 4 Atlas GP-7's so far with fantastic results. I am using the Digitrax DH163IP decoders.

I have one locomotive that isn't playing nicely though.

here is my problem that I'm hoping to get help with. The front LED comes on nice and bright when the locomotive is moving FWD. I can turn on and off the FWD LED by pressing 0 and it all works as it should. The Rear LED however is always on (not so bright) no matter what direction the locomotive is moving. The rear LED will not turn off when the locomotive is in reverse and I press 0. The rear LED does not come on full bright when traveling in reverse. It just stays on all the time (not so bright) no matter what direction the engine travels.

I just pulled apart the locomotive and changed the rear LED and resister and ran the locomotive through my Decoder Pro and still have the same problem.

Any idea's?

Mike

 

Mike,

Assuming you are plugging the decoder in the factory light board, I recommend carefully examining the board to look for solder blobs, stray wire strands or other such issues. Sometimes it is the unusual things that cause these problems.  BTW, since you have two units, swap the decoders; it is possible the decoder itself has two current paths linked inadvertently.

[Vail and Southwestern RR]

Make double sure that neither wire to the LED is shorted to the frame somewhere.  Having it lit, but dim, suggests to me that there's a short to the frame, leading to the LED being on half the time.

[jrbernier]

  You have swapped out LED's and reset the decoder - maybe your decoder has a blown rear light output?  Have you swapped decoders?

Jim

[Meyblc]

I have used my Decoder Pro to try and program the LEDs but nothing changes.

[Phoebe Vet]

Use your Decoder Pro to check the lighting CVs.  It's ever so much easier that trying to look them up.

[Meyblc]

I was thinking the same thing Tom.

How are those Ball Signal plans coming along...LOL

Mike

[tstage]

Mike,

This may be an instance where you need to adjust the lighting CVs of your decoder in order for your rear headlight to only come on bright when the locomotive is in reverse and off when going forward.  Sorry I don't remember what CVs need to be adjusted.

Tom

[Meyblc]

I'm hoping that some of the wiser & smarter DCC guys and gals can help me out here.

I have converted an older Atlas GP-7 "classic" from Dc to DCC and installed LED's with the resisters. I have done this to 4 Atlas GP-7's so far with fantastic results. I am using the Digitrax DH163IP decoders.

I have one locomotive that isn't playing nicely though.

here is my problem that I'm hoping to get help with. The front LED comes on nice and bright when the locomotive is moving FWD. I can turn on and off the FWD LED by pressing 0 and it all works as it should. The Rear LED however is always on (not so bright) no matter what direction the locomotive is moving. The rear LED will not turn off when the locomotive is in reverse and I press 0. The rear LED does not come on full bright when traveling in reverse. It just stays on all the time (not so bright) no matter what direction the engine travels.

I just pulled apart the locomotive and changed the rear LED and resister and ran the locomotive through my Decoder Pro and still have the same problem.

Any idea's?

Mike