Decoded ESU V4 LokSound 73199, 73100, LokPilot 54650 and Atlas S2 decoders

[peteski]

It is amazing how advanced model RR electronics have become. I suspect that those decoders use at least 6 layer PC boards: 4 layers for traces and then 2 power planes.  The 73100 board is also chock full of 0201 size SMD components. Those are really too small for most humans to work with.

[craigolio1]

Peteski your effort on this will help people for years to come.  Thanks very much!

Craig

[woodone]

I see 5 layers at the frame contact areas at the rear- Have not been able to count the front ones yet.
They are VERY thin!

[peteski]

Can you read the markings on the zener diode (in order to determine which part it is and thus its voltage value)?

My educated guess is that it is a Zener diode because of the way it is installed int he circuit. The markings consist of the cathode marking stripe and "2N".

[woodone]

I was wondering if I can use some Silver epoxy to repair my board? Any thoughts?

[peteski]

I was wondering if I can use some Silver epoxy to repair my board? Any thoughts?

Without seeing the actual damaged area (close up) I have no idea.  If the damage is to internal layers (and even if you know  which broken traces are supposed to get reconnected) I have doubts that you will be able to apply the epoxy precisely enough to reconnect them without connecting to other areas.  But again, withotu seeing the damage, it is hard to say.

[woodone]

It will be hard to get a good close up photo to show up.
I have been trying to see the layers using a 30 power microscope but it is too sensitive to get a good look with out loosing the spot you are trying to inspect.
Try a good camera tomorrow to see if that might work.

[peteski]

It will be hard to get a good close up photo to show up.
I have been trying to see the layers using a 30 power microscope but it is too sensitive to get a good look with out loosing the spot you are trying to inspect.
Try a good camera tomorrow to see if that might work.

30 power? Just going by what you wrote above, it seems like you will have really hard time fixing it. But I'll hold my judgment until I see the photos (if you manage to take some). 

[woodone]

I will get a few, but not today. Have 10 installs to get delivered.

[woodone]

Well no photos. I tried to take a few but no mater how I set up the camera the pictures were not clear.
So off to the other camera and a tripod.
Seeing that were are talking about the 73100 LokSound Micro Select I am going to post a photo of an N scale Kato SD70ACe I just finished.
I put some notes with some numbers on the photo. Will explain. #1 photo you have to widen the frame tabs here and be careful with the motor wire
here too. I under cut the frame so the wire would not be pinched and still used a piece of Kapton tape. #2 you have to machine out between these two tabs so the board will fit down while you to slide the board into the front two tabs at the front.  The board does not reach the front tabs (photo#3) but you still have to widen the two tabs in photo#2. I also added two very small strips of phosphorus bronze to the front of the board so they would make contact with the frame. You have to file to remove the original nubs under the front tabs so the strips will slide into the tabs.
The board is quit a bit too high, so even if the board was longer it will not fit into the slots with out removing the nubs. 

[carlso]

Woody,

Looks good. Speaker = 8x12 ? ? ?

Carl

[woodone]

No it is an 9 X 16 = 8 MM deep. I took a cut off the frame over the rear truck.
I also did two Kato ES 44 AC's, but I had them all boxed for shipment before I thought to take any photos

[peteski]

I just added the 73100 info (or most of it).  Also, following in @Steveruger45 footsteps I added dimensional information about all those decoders.

[Steveruger45]

Pete,
Thanks for the excellent and very clear explanation on the 73100 decoder.  Wonderful work that will help many of us.
I am thinking to use the stage 1 for additional caps on this decoder, purely because of the relative ease of access for the soldering iron.   

[RBrodzinsky]

Thanks Pete!