Hi Everyone,
Please take a look at this. A Digitax decoder that had works no longer works. The contacts are solid, but it only flickers when touched. Any ideas?
Hi KisNap:
You say the contacts are solid, but it seems obvious to me that there is a break in the circuit which is intermittantly being bridged when you wiggle the decoder. That suggests that the contacts may not be as solid as they appear to be.
I’m not familiar with the specific locomotive, but if the system relies on simple pressure to make the connections then that is a recipe for failure. Another possibility is that you have a broken wire. Broken wires are not always obvious. Give each wire a little tug to see if it is intact.
The best thing to do would be to hardwire the decoder. In other words, solder all the connections, or if it is not possible to solder the connections directly, get some decoder wire and solder it between the connections.
Before doing that, it would be wise to remove the decoder to have a good close look at it, and if possible test it separate from the locomotive. If you don’t have a decoder tester (most of us don’t) perhaps you have a hobby shop close enough who could do that for you, or send it back to the mfr. to be tested there. When looking at the decoder, watch for signs of cracks or burned components or traces.
Personally, I think that your problem is simply bad contacts.
Dave
Known problem with some N-scale Digitrax decoders. The Digitrax board is slightly thinner than the OEM light board and doesn’t make good contact with the frame halves.
The fix is to add a little solder to the Digitrax board to build it up where it contacts the frame halves.
Thanks for the responses. There are no wires involved either in the locomotive or on the decoder. It’s a split frame locomotive with current being transferred via the two halves. The decoder worked fine about a month ago when I installed it. Since then it’s been sitting aside until I tried it a couple of nights ago.
I had suspicions that the frame wasn’t making proper contact with the decoder, but dismissed them when I would squeeze it together and still had no power. I’ll have to try using a little pressure to see if I can get it to make contact and see if that fixes it. If it does then I can add a little solder near the contacts.
I did also place the frame directly on the tracks to take the power contacts from the trucks out of the equation, but that had no impact. Thanks again for the replies. I’ll try again tonight and report back.
If you have a multimeter check for voltage on the decoder board. Check from both rails to the decoder board to see which power feed is not working.
Starting from each rail to each item, i.e. rail to wheel then rail to frame, rail to board until you pin down the source of your problem.
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
My Model Railroad
http://melvineperry.blogspot.com/
Bakersfield
Thanks for the replies everyone. Sildering may be the solution, but before I do that I just wanted to add one more piece of information that I noticed. I noticed that the front and rear light flicker at the same time when I was tilting the locomotive. Is that some kind of signal the decoder is giving to help troubleshoot the issue? The same way a computer gives beeps when it starts up to give its status?
At least some Digitrax decoders will flash the lights if the motor leads are shorted, so yes, that’s something you’ll also want to check.
That is probably just the board making momentary contact as you are moving it around. When the decoder first powers up the headlights will give a quick flash. The reason is the decoder’s processor initially powers up in a state that turns the lights on and when the code executes it turns them off.
Tin the two pads on the decoder that slide into the slots on the frames. they ned just a little extra pressure to make good contact. BTW, Digitrax knows all about it and it won’t void the warranty.
Martin Myers
KisNap:
Stevert and Martin Myers seem to know exactly what the problem is so if I were you, I’d follow their advice by adding a wee bit of solder to the tabs.
I strongly recommend putting a bit of non-acid soldering flux on the tabs before hitting them with a freshly cleaned soldering iron tip. I would then melt a little solder on to the tip of the iron and then touch the iron to the tabs. You want the added solder to be clean and shiney once it is deposited on the tabs, but you don’t want great gobs of it! Don’t hold the iron on the contacts for more than a second or two. Otherwise, you may damage the circuit board traces.
Hope this solves your problem!
Regards,
Dave
Well, I know what I’m doing tonight. I tried reinstalling the decoder last night making sure that the motor tabs are making contact and that they’re not touching. I’ll try adding a small bit of solder to the 4 contacts and hope for the best. I’ll report back whether that helps or not. Thanks for all of the advice!
Hi…i am new user here. As per my knowledge the best thing to do would be to hardwire the decoder. In other words, solder all the connections, or if it is not possible to solder the connections directly, get some decoder wire and solder it between the connections.