I am trying to instal point motors with the digital control in the C track. I have a keyboard, One point motor starts to buzz and heats upo within seconds when turning on. The other just does nothing except when I change the points manuaaly it immendiately changes them back again. Have foloowed all instructions and it is driving me mad...can anyone help
Regards
David

David,
differently from Charlie I guess you mean decoder with your "digital control"; however it's not quite clear. And as you have something wrong, I think you had better describe your setup and connections more thoroughly. So far I can only say that you have not a wery common error, which causes me to suspect some misunderstanding or connect mistake.

Regards,
Lars

Hello David and all,
just for my information, what decoder are you using for your turnouts? It sound like if you have constant voltage on the decoder's output, as if you were using K84 instead of K83. Assuming you're using the right decoders (K83 or equivalent), I'd verify the output transistors of your decoder. If the are burned out, will put constant votage on the output connections, thus causing what you see. Try with an Ohmmeter to measure the resistance between collector and emitter, in both directions (switching red and black wires). You should see about 30-50 Ohms in one polarity and high resistance in the other. If you have low resistance in both directions, something is wrong, you should try to replace the transistors. Hope this can help.
Regards,

David:

Make sure the keyboard is firmly inserted into the socket on the side of the 6021. There are clips provided to make sure this connection is tight. If one or more of the contacts are not making good, you get very unpredictable results

Oh. Well it comes up with the state it "remembers" from the last time it was used. That could be all red.

Sorry to ask these basic questions, but:
What controller are you using? A 6021? Intellibox?
Is the Keyboard firmly connected to the left side of the controller?
Are all "browns" together on the layout?
Are the track connector cables connected correctly from the decoder to the track (brown to outer rails, red to the centre stud rail)?
Is the turnout motor connected correctly to the decoder? (and not to the track itself)....

Hi David, I believe that could be important to try to determine where is the point of failure.
There are three components that could be failing (assuming the connections are ok):
The Keyboard, the Control Unit and the decoder.
You can separate the Keyboard and then power up your system and see what happens. Should the problem persist, the Keyboard is not the failing component.
Make your tests with the turnout dismounted from the layout to avoid any connection problem.
Once you've discarded the Keyboard as the problem component, try with a different decoder and no Keyboard.
In regards to track connections, brown wire goes to the terminal marked 'O' (or zero) and red goes to 'B' (Betrieb).
Should you want to have an interactive help (if I can help you...) , you can find me at 'jorge_vilarrubi@msn.com' , please remember we have some time difference.
I'm posting this reply at 21:00 local (Argentina) time. I believe we are GMT + 4, please check this.
Regards,

Hi Guys

Many thanks for replies. Tried everything I think. Transformer to contoller is wired Yellow to Yellow and Brown to Brown. Contoller to track is Brown to Brown and Red to Red. Digital decoder is plugged in to turnout and then the red and brown wires attached to track. The turnouts buzz and heat up even with the keyboard detached. Other times they just do nothing. Turnouts seem OK and it is unlikely that two new decoders are faulty. Have reached the end of the road timewise on this and am considering buying an Intellibox which sems to do everything. Is this a good idea.
Regards
David

Hi David:

I really can't go through all responses to see if somebody gave the same answer with me. Sometime ago I was getting a buzz with a C track turnout and If I remember correctly there was a short circuit somewhere along my cabling. Have you connected the red and brown cables of the decoder to "B" and "O" respectively on the track? Have you checked this?

The Intellibox IS a good idea, but I doubt it will solve your problem. With the keyboard disconnected (and the 6021 rebooted) and the problem remaining, I'm convinced that the problem lies in the point motor, or the connection between the motor and the decoder. But very strange that it works OK with the analog cable and connection. What happens if you have the decoder connected to the motor, but disconnected to track? What happens if you press green and red buttons on keyboard, does the buzzing turnout throw? When it buzzes, what happens if you switch int manually? The interal end shutoff contact should disallow any buzzing when finished even if the decoder doesn't shutoff properly. Or you've got a short somewhere.

/Lars

Hi David, don´t give up!
There is another possibility: the metal box of the turnout motor can touch the metal plate under the pukos. At the same time, there is an inherent problem in these motors: the flange of the metal box, at the end of the motor where the wires are connected, can sometimes touch the track in the PCB corresponding to the yellow cable. When turnouts are operated in analog mode, this can lead to a damage in the output transistors of the 6021, because AC is fed to Red output. Maybe this can cause other problems in digital mode. I discovered this the hard way, when my IB was damaged. I isolated all motors from the puko's plate and twisted the metal flange of the motor box to avoid contact with the PCB.
Did you test the motor and decoder dismounted from the turnout? This could indicate if you have a bad connection via the puko plate.
So far we know that the Keyboard is not responsible for the problem, since you have the same failure when detached.
We have only to components under suspicion: the decoder or the 6021. (assuming no errors in the connections)
Try some more testing with both motor and decoder detached from the turnout and with more than one decoder. If the failure persists, you should try a test with another 6021.
Regards,

Thanks again for your help. However I am now laying track and getting some trains running which will take some time as my layout is fairly large. With the 6021 doing all it should with the locos I presume it is OK and I dont have another one to try it.
This is a great site and I have been very pleased with the numbers who have replied and offered help. I have been in model railways for over twenty years now but only just change to Marklin so will learn the system as I go along. I will leave the point motors for now and return to them at a later date.
One final question which someone may know..is it possible to convert Trix DC locos to run on C track three rail by changing pick ups etc.
Best wishes to all
David

Hi David, DC locos run perfectly on C track if you use R3 as a minimum and 12° long turnouts. I have several Rocos, Fleischamnns, Trix, Katos, Liliputs, Brawas, all running ok. The only problem could be to have enough room for pickup and decoder, as Lars indicated.
Uhlenbrock 76520 decoder is smaller than LokPilot, with similar characteristics. Both can be programmed with a 6021.
Regards,