Digitrax DN163K4A/B LED Questions

[cbroughton67]

It looks like the DN163K4A and DN163K4B are the same board, except for the location of the F0r LED; the A has it mounted on the top-rear of the board (considering the backwards placement in the Kato ALC-42), and the B has it mounted on the bottom-front of the board for illuminating the front marker lights when the locomotive is in reverse / push mode.


My question is, can the LED missing from either board be added, so that the A version will light the marker lights, or the B will light the rear headlight? Or, are there other differences between these two boards that I'm unaware of that would prevent this from working? Full disclosure - I soldered a wired 0603 LED to the bottom-front of a DN163K4A (I also swapped the leads, since I didn't know which is the + pad), but it didn't respond when F0r was on.


TIA,
Chris
 

[peteski]

Not familiar with that decoder , but I took a look at https://www.digitrax.com/media/apps/products/mobile-decoders/dn163k4a/documents/DN163K4A.pdf

The photo of the bottom of the decoder seems to show that there is a trace from one of the bottom LED pads to the F1 solder pad.  It that is true (they are connected) then the bottom LED is controlled by F1 and you would have to remap the function keys to how you want it to work.  I'm also not sure if the resistor is populated on the boards there are some empty pads on the top of the board.

Odd thing is that the specs sheets for /DN163K4B https://www.digitrax.com/media/apps/products/mobile-decoders/dn163k4b/documents/DN163K4B.pdf shows what looks like hand-soldered LED on the bottom, but no mention of it is made anywhere.