Address change on DCC Bachmann GP7

[wljacpa]

I have a new MRC Advanced2 DCC controller.  It will not change the address of my GP7.  I have tried multiple times on both the program track and the main line.  A couple of other locos changed without incident.  My older Bachman EZ controller changed it easily in the past.  Any ideas?

[seadowns]

Hi!

Can you write or read any other CVs?
What about a decoder reset? CV8 to will do the job, then start up again with programming the adress.

Regards
Mathi

[wljacpa]

Thanks for responding.  Guess I don't know how to do a reset.  Does not seem to read anything much; however,  CV 8 read "008".  How do I reset?

[seadowns]

Oh I'm so sorry!

I've forgotten to check my post.
A reset is to be done by writing the 8 into CV8.

[wljacpa]

I have done that, doesn't change anything.  Thanks for the help, however.

[Ken G Price]

Since this is the only engine that has this problem, then the decoder may not be making good contact somewhere, or it is defective.
Check for loose wires first.

[railtwister]

I have found that when I have a problem trying to program a specific loco, it usually works if I change programming modes. It seems my GP7 responded to Direct Mode. I use a SPROG II interface connected to a laptop running free JMRI DecoderPro software. Some decoders will not program in Direct Mode, so I try Paged Mode. It also depends on which mode your system defaults to. Another thing to try is POM (programming on the main), but not all systems are capable of this. Check your system owner's manual to see what modes are available on your system, and the paperwork that came with your loco or decoder should tell what programming method is preferred for that decoder.

Bill in FtL

[Ken G Price]

Bill, good idea. I have had to change the programing modes twice from the default while using the program track.
Don't know why, but it worked.
If I program on the main (which I have also done to get a decoder to program) I have to remember to remove all of the other engines otherwise it will change all.
The voice of experience.

[MichaelWinicki]

I'm also having problems changing the address on my (new) Bachmann GP7.

I have an MRC Wireless system and have never had a problem before changing the address of any locomotive in my fleet including 3 other Bachmann's that were purchased previously.

This GP7 refuses to have its address changed.

Here are the steps I'm going through:
1. I'm attempting to reprogram it on my programming track (just like all my other locos).
2. I'm attempting to change it from "3" to "5608" which is the number on the cab.
3. The headlight changes in lighting intensity as I input values... So I know the decoder is receiving some sort of signal.
4. I take the loco off the programming track, put it on the main, punch in 5608 and nada.  I punch in 3 and all is good.  Argh!

I've also tried reprogramming it through the CV's and that does squat too.

I may be forced to call Bachamm service...

[skipgear]

Pull the shell, lift the decoder board slightly and bend the contact tabs down so they make better contact. I have done tow like that for a friend that owns 20 of these for his very large layout. They were the only two he had problems with and after tweaking the contacts, they have run flawlessly ever since.

[seadowns]

Hi!

To force more tension to the wipers I glued some peace of  insulation remains which are stripped of copper wires. These are "tube shaped" and springy enough to support the wiper contact.

Regards
Mathi

[mywhitedog]

I pulled the decoder out of my GP7, and replaced it with a Digitrax DZ125 with BEMF. WOW what a difference!! It's the smoothest running Bachmann loco I have now, I am now considering pulling the decoder out of the DD40AX and replacing it with a Digitrax decoder. For the lights I used a light board removed from a Kato loco, cut the traces and replaced the LED's and added the resistors. No cutting or milling required. It's quiet and smooth running in both directions, before it was jerky and reverse was poor. I tried everything listed here and nothing made it run right. Once it stopped running I pulled the board tested the motor with a DC power pack, it ran smooth, so I ditched the decoder and installed the DZ125.

[railtwister]

Don't overlook TCS decoders, too. My best running N scale locos have TCS decoders, and they run very smoothly. The TCS drop-in decoders have very bright LEDs that cast a light beam in front of the loco. I must say that I haven't needed to change decoders in any of my Bachmann DCC equipped locos so far (although I have had to tweak a set of contacts on one board), and both my RS3 and GP7 run quite well.

Bill in FtL

[mywhitedog]

I tried all the contact tweaking, just would not run smooth, I already had the Digitrax decoder so in it went, made a huge difference, the GP7 decoder went into a GP40 loco I had.

[wljacpa]

I put my GP7 on a shelf for a while.  Finally took it down and thought I would try some of your suggestions.  Banged it around a bit but could not get the shell off.  Tried again to change the address and it worked like a charm.