Hi all
Running into a problem with a DCC install on a P42 DCC ready loco. Runs fine on DC. Installed a new DH123. Lights respond to direction change but no loco movement. Put that decoder in another loco, runs fine so not a decoder issue. Any suggestions?
I did notice the a component on the Athearn board gets hot. Perhaps a board issue?
bagal
Hello All,
A few questions...
8-pin NMRA plug to 9-pin, Digitrax harness, after removing the dummy plug? Solder- -hardwire- -the decoder?
Answering the above questions can assist the great folks on these forums help you find a solution.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
jjdamnit Which DCC system are you using? Lenz Are you also using the same DCC system for programming? Yes, although no programming initially Is the testing of the installed decoder being done on a programming track? Main initially What address did you assign to the decoder, if any? Initially default 3, subsequently 44 on programme track. How is the decoder installed: 8-pin NMRA plug to 9-pin, Digitrax harness, after removing the dummy plug? Jumper board removed, then decoder plugged into the 9 pin connector. Solder- -hardwire- -the decoder? Would prefer not to but may have to.
8-pin NMRA plug to 9-pin, Digitrax harness, after removing the dummy plug? Jumper board removed, then decoder plugged into the 9 pin connector. Solder- -hardwire- -the decoder? Would prefer not to but may have to.
Install is same as on another P42. Remove jumper board, plug in decoder.One works fine, the other doesn't.
I believe you answered your own question. Can you tell us what is getting hot on the Athearn motherboard? Resistor? Coiled choke? Capacitor?
I remember quite a few years ago Bachmann had a board that you had to cut a couple of things from the board or the decoder would act up and have poor motor control.
Pete.
Thank you for your quick response.
bagalInstall is same as on another P42. Remove jumper board, plug in decoder.One works fine, the other doesn't.
Good to know!
A few more questions...
Have you confirmed that pin 1 on the NMRA 8-pin to 9-pin Digitrax harness is indeed in the number 1 socket on the PCB?
If the 8-pin plug is reversed the motor won't work, but the lights will.
From what you describe, it seems power is getting to the decoder through the wheel pickups, which provides power to the other functions but no motor movement.
If the lights work but the motor doesn't, I would look at the connection between the PCB and the motor.
How are the wires going to the motor connected to the PCB, soldered, or slide-on connectors to tabs on the board?
The slide-on types are notorious for a poor connection between the solder tabs on the PCB and the wires.
Keep us informed and...
jjdamnit A few more questions... Have you confirmed that pin 1 on the NMRA 8-pin to 9-pin Digitrax harness is indeed in the number 1 socket on the PCB? Doesn't use the 8 pin socket, decoder plugs into the 9 pin socket. If the 8-pin plug is reversed the motor won't work, but the lights will.I thought if an 8 pin was reversed, mnotor still works but reversed? From what you describe, it seems power is getting to the decoder through the wheel pickups, which provides power to the other functions but no motor movement. Correct, power to lights, but (apparently) no power to motor. If the lights work but the motor doesn't, I would look at the connection between the PCB and the motor. Maybe, but motor works fine on DC. How are the wires going to the motor connected to the PCB, soldered, or slide-on connectors to tabs on the board? As ex factory, slide on connectors. The slide-on types are notorious for a poor connection between the solder tabs on the PCB and the wires.Agreed, they are not great.
Have you confirmed that pin 1 on the NMRA 8-pin to 9-pin Digitrax harness is indeed in the number 1 socket on the PCB? Doesn't use the 8 pin socket, decoder plugs into the 9 pin socket.
If the 8-pin plug is reversed the motor won't work, but the lights will.I thought if an 8 pin was reversed, mnotor still works but reversed?
From what you describe, it seems power is getting to the decoder through the wheel pickups, which provides power to the other functions but no motor movement. Correct, power to lights, but (apparently) no power to motor.
If the lights work but the motor doesn't, I would look at the connection between the PCB and the motor. Maybe, but motor works fine on DC.
How are the wires going to the motor connected to the PCB, soldered, or slide-on connectors to tabs on the board? As ex factory, slide on connectors.
The slide-on types are notorious for a poor connection between the solder tabs on the PCB and the wires.Agreed, they are not great.
The parts getting hot might be diodes or resistors. They are related to the lights. There are two, which gets hot depends on whether front or rear lights are on.
One more question. Are you using the NMRA 8 pin plug for the decoders? The reason I ask is sometimes the pins on the plug can be too long and go through the motherboard socket and actually touch the metal frame or the top motor brush keeper. I have seen this a few times.
wrench567 One more question. Are you using the NMRA 8 pin plug for the decoders? The reason I ask is sometimes the pins on the plug can be too long and go through the motherboard socket and actually touch the metal frame or the top motor brush keeper. I have seen this a few times. Pete.
I think I have found the problem. Looking like the motor wasn't properly isolated. i will try a piece of tape between the lower motor contact strip and the frame.
That would do it. Why it didn't let the smoke out of the decoder is beyond me. Your lucky. Did it run on DC? Was it tested on DC?
Hi Pete
Yes, it was run on DC before the install. Ran very nicely. I lifted the motor off the chassis and it would run, so reassembled with a strip of tape under the motor assembly, and all is good. There is a wire soldered to the brass strip under the motor. I think that blob of solder was making contact with the frame.
bagal Hi Pete Yes, it was run on DC before the install. Ran very nicely. I lifted the motor off the chassis and it would run, so reassembled with a strip of tape under the motor assembly, and all is good. There is a wire soldered to the brass strip under the motor. I think that blob of solder was making contact with the frame. bagal