Help! CVs have changed on their own!

Hi

I am in the building stage of my layout and so use my locos to prove track and make sure everything is running OK. I am not into changing CV addresses or anything to do with CV’s (yet) so need help please!

My BLI HO PRR M1a 4-8-2 with sound running with NEC Power Pro DCC was working fine but out of nowhere the horn button has become the bell and when I press the bell button, nothing happens. It is only this loco that this has happened to.

I haven’t accessed any CV changes that I am aware, the only programming I have done is to allocate switches through Switch 8’s to switch through NEC accessory select.

Help please!!!

Thanks in advance

Barry

Barry,

Sometimes a short will cause an issue by changing CVs. It’s completely random when in happens in my experience. You just change it back and presuming it doesn’t happen again, the issue is solved.

You’ll want to look into Function Mapping to correct this, as it assignswhat function corresponds with what key on the controller.

Thanks Mike

Interesting about shorts. I have been tracking down (and found) a short out problem this last few days.

Thanks again.

Here is the section from the manual with instructions to re-set the decoder to factory defaults:

RECOVERY PROGRAMMING (Option 7) [press the Prog/Esc key seven times]
This programming section is included to allow the user to set all registers of the Decoder to the values that were programmed into it at the factory.

[This will appear on your screen]
RECOVERY
PROGRAM 1=YES

Press 1 to enter Recovery mode. [The system will then rapidly scroll through all of the CV’s.] This will reprogram NCE decoders (and most others) to their original factory values. It will also set addresses, motor control CVs and Function Mapping CVs to a useful state so that you can get control of a decoder.
As each CV is programmed the CV number is displayed.

Good luck!

While this will work well with a NCE decoder, I doubt it will be usefull with a sound decoder.

Hi Roger

So I assume this means I will have to re-program everything again. All 4 Switch 8’s and assign all my loco’s again?

Thanks

Barry

You really don’t want to use the NCE reset function unless you have a NCE decoder.

And no, you don’t have to reset everything. Only the involved loco.

No. Put the subject locomotive only on your program track, then do the reset. As noted it may not completely reset a non NCE decoder but in my limited experience it has reset everyone I have done, including several non NCE decoders and including a couple of sound decoders (QSI’s). If it doesn;t work on your decoder you aren’t out anything but a few minutes time.

The problem is that the NCE reset doesn’t actually reset anything, it sets a set of known CVs to known values. Some of the CVs it changes are standard NMRA defined ones, which apply to mostly all decoders, but some of the things it changes are CVs that aren’t so strictly defined and may have slightly different meanings with other brands. Best to use use each manufacturer’s reset process, which in many cases revolve around programming CV8 (which is not really writable) to a value which triggers the decoder to do the reset. Some others use CV30 as a reset.

–Randy

Hi

Just remembered that the BLI loco comes with a magnetic ‘wand’. Pass that over the loco and it returns to factory set up. (I believe.) Now have to hunt down the ‘wand’!

Thanks as ever for all your help so far guys.

Barry

Barry,

Is the decoder by QSI? If so, and if you cannot find the magnetic wand, put it on the program track and change the CV’s as follows:

CV 49 = 128
CV 50 = 255
CV 56 = 113
This should reset the decoder to factory values.
Also, I think I misstated the NCE recovery steps incorrectly. It should be:

Hi Roger

Yes it’s QSI. Thanks for this. I’m caught up in other things at the moment but will give this a go when I’m free. Thanks again!

Barry

The NCE programming values listed will have no effect at all on a QSI decoder, so don’t even bother with them.

Cacole,

I have early QSI decoders that came factory installed in PK2’s by LifeLike and in a switcher by Broadway Limited. Both manuals have specify those values as does the Quantum NMRA Reference Manual v 3.0 on page 105 and on page 363 of the most recent v 5.1.1 version.

So I am curious about why you say changing those CV’s to the indicated values will have no effect on QSI decoders.

What I was referring to is the NCE Recovery Steps – they work only with an NCE decoder and will do nothing to QSI or any other brand.

[quote user=“skagitrailbird”]

Barry,

Is the decoder by QSI? If so, and if you cannot find the magnetic wand, put it on the program track and change the CV’s as follows:

CV 49 = 128
CV 50 = 255
CV 56 = 113
This should reset the decoder to factory values.
Also, I think I misstated the NCE recovery steps incorrectly. It should be: