!!

Not Registered?

Welcome!  Please register to view all of the new posts and forum boards - some of which are hidden to guests.  After registering and gaining 10 posts you will be able to sell and buy items on our N'porium.

If you have any problems registering, then please check your spam filter before emailing us.  Hotmail users seem to find their emails in the Junk folder.


Thanks for reading,
The NGF Staff.

Author Topic: Trying to see DCC and program DCC chip  (Read 279 times)

0 Members and 1 Guest are viewing this topic.

Offline Sharkey51

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 15
  • Country: au
  • Gender: Male
    • Awards
Trying to see DCC and program DCC chip
« on: January 16, 2020, 07:32:10 AM »
I had a lokpilot nano DCC chip wired in to a Poole-built Prairie. It wouldn't start one day and I suspected maybe the motion stalled and I overloaded the motor and cooked the chip.
So, I  fitted a new chip - but when I put the loco on the track to program it, my z21 controller couldn't see it.
I removed the new chip and successfully ran the motor dirctly on 12v DC by applying power directly to the brush clips, so no problem with the motor.
I've reconnected the chip. Still no joy on the track  However, if i apply the DCC power/signal directly to the connection points for the black and red wires that draw power from the wheels, then the z21 sees the loco and the chip!
I have checked the continuity from the wheels to the chassis connection points just described. They are both very low resistance connections - so one would assume that the signal should be able to get from the wheels to the chip - but no!
So,  I'm stumped over what to try next.


« Last Edit: January 18, 2020, 05:08:42 AM by Sharkey51 »

Offline NinOz

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: Ex3504
  • Posts: 776
  • Country: au
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #1 on: January 16, 2020, 09:31:39 AM »
If it were mine I would be checking current draws.  Not knowing how you have performed checks so far, it does seem like a continuity problem from track to chip.
Check the replaced decoder to see if it is/was ok.
To be called pompous and arrogant - hell of a come down.
I tried so hard to be snobbish and haughty.

| Carpe Jugulum |

Offline PaulCheffus

  • Trade Count: (+1)
  • Full Member
  • ***
  • N Gauge Society Number: 4575
  • 2mm Association Number: 4172
  • Posts: 1348
  • Country: gb
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #2 on: January 16, 2020, 11:09:54 AM »
Hi

From your comments above it appears you are trying to program the decoder on the main layout. You can't read CV values in this wayunless you have something like railcom.

Do you have a programming track? This is where the CV values should be read back.

Cheers

Paul
Procrastination - The Thief of Time.

Offline Vonzack

  • Trade Count: (+2)
  • Full Member
  • ***
  • N Gauge Society Number: 20933
  • Posts: 504
  • Country: gb
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #3 on: January 16, 2020, 11:44:28 AM »
Hi,

If you have had the loco working by connecting the red and black wires to the DCC Feed directly, I'd suspect you have a short somewhere between the track and chip. It seems you've been able to rule out everything else with your other tests.

Does the command station show / detect a short?

Can you run other loco's with the Prairie on the rails?

Cheers, Mark.

Online LASteve

  • Trade Count: (0)
  • Full Member
  • ***
  • N Gauge Society Number: 28183
  • Posts: 446
  • Country: us
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #4 on: January 16, 2020, 10:00:28 PM »

I have checked the continuity from the wheels to the chassis connection points just described. They are both very low resistance connections - so one would assume that the signal should be able to get from the wheels to the chip - but no!



Have you checked the resistance between the track (not the wheels) and the connection points? That would eliminate the possibility that your track/wheels need a good clean

Also, just as an FYI, I'd put a piece of heatshrink on your top clip either side of the brush spring contact, around the shoulder of the clip and down to the bottom. It eliminates the possibility of a short between the clip and the chassis (a problem I had on a Poole 08 conversion to DCC).

Offline Sharkey51

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 15
  • Country: au
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #5 on: January 16, 2020, 11:51:12 PM »
No shorts indicated on the z21. No shorts detected across the various parts of the loco. I can run another loco with the dead Prairie on the same track. The resistance between the track and the chip feeder wires is very low 1-2 ohms max - about the same as it is from the wheels to the chip feeder wires.
« Last Edit: January 18, 2020, 05:10:43 AM by Sharkey51 »

Offline Sharkey51

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 15
  • Country: au
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #6 on: January 23, 2020, 08:37:44 AM »
I'm about to purchase a new set of wheel pickups - on the basis that there must be some sort of signal loss or interference between the wheels and the pickups - since I can get the chip to perform without a problem when I bypass the wheels altogether and go directly from the track to the power input to the chip. It's the only thing left that I can think is causing the problem .... unless there are any other ideas out there.

Offline Malc

  • Trade Count: (+3)
  • Full Member
  • ***
  • N Gauge Society Number: 21878
  • Posts: 4678
  • Country: gb
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #7 on: January 23, 2020, 08:18:08 PM »
Not necessarily a solution, just a query. Did you remove the interference suppressor when fitting the chip. I have a few 08s to convert.
The years have been good to me, it was the weekends that did the damage.

Offline Sharkey51

  • Trade Count: (0)
  • Full Member
  • ***
  • Posts: 15
  • Country: au
  • Gender: Male
    • Awards
Re: Trying to see DCC and program DCC chip
« Reply #8 on: January 23, 2020, 09:50:05 PM »
I have removed the capacitor on all 8 of the Poole-built locos that I have converted. All are running fine - except one! Even that went okay for a while - so I'm thinking it's a connectivity problem.

 

Please Support Us!
February Goal: £60.00
Due Date: Feb 29
Total Receipts: £65.00
Above Goal: £5.00
Site Currency: GBP
108% 
February Donations


Advertise Here
anything
SimplePortal 2.3.5 © 2008-2012, SimplePortal