Installing a Digitrax DN163A3 into an ATLAS MP15-DC

As I pointed out in an earlier blog I've made the decision to use DCC.  Well, let's be honest, it wasn't much of a decision - the advantages are legendary.  However, every loco that I will be using needs to have a DCC mobile decoder in it.

Digitrax DN163A3

One of the locomotives, the Atlas MP-15DC (a common CP Rail yard worker) was DCC ready - very confusing as it doesn't mean it can run in DCC rather it can take a DCC decoder without soldering.  I purchased the Digitrax decoder and set out to install it !

Now keep in mind that I'm pretty handy with computer parts and general building etc.  Back in the day I built hundreds of 486 and Pentium computers.  Those were in the days of multiple jumpers, voltages and all sorts of nasty trickier with IRQ assignments etc.  Then Plug and Play came along and things changed (for the better) but I digress.  Suffice it to say - I'm comfortable taking things apart and putting them back together.

Being the first time for doing this I decided to read the instructions.  Seemed pretty straight forward.  Take the loco's case off, unscrew a couple screws, loosen the onboard DC controller remove it and then put in the new Digitrax DCC one.  I studied the pictures, and the real items and thought I was ready.

The Atlas MP15-DC

Then it occurred to me - how the !#$!@ do you take the case off !?  The instructions don't tell you.  The little parts list that comes with the loco don't.   Friends?  I don't have any interested in trains.  Google ?  oh, yes, there's a funny guy on Youtube that shows how to use a storage case and a 2" drop to remove all manufacturer's motor cases.  Real funny - worked for him, worked for me? of course not!  I'm thinking that his cases were looser than a stripper in Tijuana.   More googlin' , followed by more and more reading.  Finally I found something !  and it worked ! you can use a tiny screw driver to loosen and pry the back off.  After an hour lost and a broken handrail on the unit, I was back on track.

!@##! case is off

So now all I had to do was loosen the two screws a bit and  wiggle the DC controller card out.  Once again the instructions failed to mention a couple things.  Like the wheels fall off as soon as you touch the screws.  This was a bit surprising...  then I loosened too much and the whole thing fell apart into pieces, the motor, crank shafts and all these little parts ended up on the table.  The DC card was still firmly nestled in the frame though.  of course.  I took that out and then put everything back together with the Digitrax decoder in but I couldn't screw it together, something was out of place.  I took everything apart and tried again.

Note the split in the middle - the frame is two halves with the motor nestled in the center.

Long story short, 3 hours later I had it assembled (about the 15th time) and was ready to try it out.  Naturally I didn't have any track down at that time so I wired up some savage track work.  Of course that didn't work until I soldered the leads to the damn track.  With fingers crossed on turned it on and voila !  the light came on.  Very exciting, so I gave it some power and it crawled along a bit !!!... triumphant I tried to get the case on but the frame wasn't screwed together well enough.  Thinking I was an expert now, I unscrewed it and tried to figure out why the two halves weren't coming together.  I re-assembled it after making an adjustment on one of the crank shaft assembly.  It seemed to work - at least the shell could fit.  I tried a short run with it ... but only the light went on.  no power. I said some nasty things and then went to bed.

The next couple days I tried everything I could think of but to no avail.   The thing just didn't want to work.  So I did the only thing I could think of... I gave up until I had some bolt of lightning inspiration.

Two months passed and the LHS (local hobby store acronym) had a sale on an MP15 - not a CP but I was really only after the motor as I thought the DCC decoder wasn't working because of a grounding fault.  So I picked one up.


This time I installed it the right way... and then NOTHING!  I was a bit pissed - to say the least - so I took a whole lot of pictures and prepared to send them to Digitrax asking what the issue could be, thinking it might be the decoder (in all the fuss I might have smoked it).  So I went to their web page and to the decoders instruction pdf (just in case).  I read it.  Then I looked at the picture.  I looked at it again.  I noticed the words that I should have seen two months ago - the LEDs go up.  My board was upside down.  Now its all fixed up and running beautifully.

That's my first experience with a decoder install and I'm amazed at my own stupidity.  I've got another one coming up for a KATO P42 Genesis Via Rail locomotive that I can't wait to try.


Assuming I can get the case off.