I recently won an auction on Ebay for an N scale Atlas Dash 8-40B. It was advertised as needing a new decoder.
Once received I tested it on DC and DCC, and as advertised, it did not work.
The next day I started looking for a replacement decoder so I went to Tony’s Train Exchange knowing they are experts in DCC. I went to the Decoder Comparison Matrix where I found another link at the top of the page for a Decoder Installation Handout. The handout tells you which decoder best fits the loco. In my case a Digitrax DN163A0 was the decoder I needed. However it costs $29.75. Almost doubling the cost I paid for the loco.
I then noticed at he top of the Decoder Comparison Matrix page there was a link to HOW TO RESCUE A FAULTY DECODER. I read through information and found that 33% of returned faulty decoders can be corrected by resetting it.
I printed out the information to reference while resetting the decoder. It gives you manufacturer information and which CV to change.
Atlas uses Lenz decoders so I used Lenz’s defaults to reset the deco
The ability to change a decoders CV settings gives an engine a multitude of customized features. Many modelers only go as far as changing the decoder’s default address from 3 to the cab number. A common fear is that if you enter the wrong value, lose control, you may end up in limbo without the ability to recover or correct the problem. Also, sometimes a track short circuit may cause some decoders to get corrupted and not respond correctly. Good news! There is generally a simple solution. Most decoders have a way to restore the decoder CVs back to factory default settings … much simpler than trying to figure out which CV was causing the problem!
According to the manufacturers, many of the decoders returned for repair could have been rescued if they had been first reset to factory settings. I talked with one decoder manufacturer who said at least 33% of their returned decoders are “fixed” by using the simple reset procedure.
Since the factory reset is not in the NMRA DCC standards or recommended practices, each manufacturer can do their own thing. If you do not know the manufacturer of your decoder, you can try reading CV8 on the program track. This is a read only CV that has the manufacturer’s ID number (numbers shown in decimal).
Here is a chart that lists the most common IDs and reset procedures. For other decoders check the manual for CV and value used to reset to factory settings. All these decoders do support Ops Mode programming and can be reset on the mainline assuming you have control of the address.
If you do not have control of the address use the program track.
That’s exactly what I printed out to reset the decoder. Notice the manufacturer number for Lenz is 33. When I brought up the manufacturer number on my NCE it read 127. Because the Atlas box said it had a Lenz decoder I went with their CV settings.