Hi all, Yesterday i picked up 3 Digitrax decoders (Not sound, just regular), one for a FVM GEVO, one for a Kato P42, and one for a Kato SD90MAC. The Fox Valley model could not have been easier. It was just a 6 pin plug and play. Programmed the address and she was off to the layout and running like a champ, I haven't opened the one for the P42 yet so nothing to say there yet Next up was the SD90MAC. It looked like a very simple install as well. Quick DC test run was good. Shell off, lightboard installed and new decoder ready. Lightboard removed. Slid right out. Kapton tape applied as directions that came with decoder and several You Tube videos I watched. Brand new right out of the package decoder in place. Seems to fit perfectly Now up to the track hooked to the BLI address changer And POW, nothing, no decoder detected. Double checked that it was installed correctly and the fit was good. Moved over to check the decoder with my Zephyr. Tried several time to get a shot of it flashing ND when I tried to read the address but it was faster than my finger on the picture button so all I got in 5 tries was this shot so you have to just use your imagination to see the flashing ND So now the BIG question, am I doing something wrong or did I get a bad decoder?
Make sure the decoder tabs are contacting the frames? Symptoms say no power getting to the decoder. Maybe a touch of solder on the pads?
Disregard my two prior comments! You have the board installed correctly. The board needs to be slid further forward to the left to secure the contacts under the frame tabs and get the thicker part of the decoder, to the right of the motor contacts, to lock into the frame in the short slots located there. You only need to move the decoder about an eighth of an inch or more to lock it in. If this doesn't work with only one pair of contacts getting power to the board, you need to be sure those two points of contact are more or less firmly making constant contact as MK stated in his reply. If you are skilled in soldering a very small addition of solder to those copper contacts on the top or bottom would help tighten the board. The motor contacts can also be soldered to the board to help keep power more constant. If you don't have soldering skills or feel secure enough adding a small amount of solder to the board, adding very thin shims (.005") of plastic under the contact points when you slide the board in might be enough to hold the board tight and make good electrical contact. Sorry about the first two posts with the wrong info. Hope this post is a better solution and you get your power on the road. John
I think when I retried it after the picture, it did slide in more. I'll retry it and see if that helps. New picture in a bit
These contacts on each side that go under the copper wings on the decoder board, right? They are super tight. I will try and clean them too just in case. I slid the old board back i place and it worked on DC again fine. The copper wings on the decoder, while the decoder is out, should I be able to just touch those to the rails and read the decoder?
The 2 small contact points that slide into the frame are the points you need to attach to your DCC system to read the decoder. Having a decoder tester is the best way to check you decoder. If you don't have a decoder tester (I assume this is true) you should have a pair of alligator clips that connect to you DCC programing wires. You can attach the clips to the decoder where the 2 frame contact points (the small copper pads on the left in the photos) are, making sure they don't contact any other parts of the decoder or have another contact point that can cause a short when trying to read the decoder. Don't use the motor contacts to test the decoder using the rails or loose wires! I'll try to post a photo in a little while to show a safe way to test a decoder without a tester. It will probably be about 45 minutes before I can get to it. John
Do Not Use the motor contacts on the decoder to test it on DCC or DC ! I sent you a PM and need to have you reply to that if you can. Thanks John
tpwillie has a point and I think that might be your problem. In your picture, there is contact showing and a gap between the decoder and the frame. Here is an installation picture from TCS' website. Different manufacturer but same decoder foot print. The contacts are pushed way in and there is no gap between decoder and frame.
So you guys are right that in the picture, it's not seated good. Here's another look after I worked with it more and made double sure all the different contact points were making solid contact. Still got nothing from the decoder. So as was suggested, got some alligators clips and hooked up to it that way and still nothing. At this point and after a very nice conversation with a fellow TB member, I'm pretty sure it's DOA. On a positive note, after messing with that, I did do the install on the P42 and it went super smooth so I was 2 for 3 today on decoders. This will get sorted out and all will be good at some point. These went much much better overall than an attempt I had made with an Atlas engine. We'll not revisit that one. Now on to other stuff. I appreciate all the comments and tips. You all are GREAT!!!! THANK YOU!!!!
It was indeed a bad decoder. The replacement is in transit back to me and due sometime this coming week.
Quick update. Replacement decoder arrived late yesterday. Installed today and works perfectly. Thanks all for input and advice. Glad it turned out to be a faulty decoder and not something that I did wrong.
No worries we have all been there and done that before! I have had my share of successful and unsuccessful decoder installs, it is all part of the learning process.
