New Guy....Actually the system wasn't a fault per se. I'll try to explain in simple terms. In DCC you want to be able to programme certain parameters in a decoder so every system has that ability to varying degrees.
Basically you have "Programming on the Main" and "Programming on the Programming Track". Google those two terms for a much more complete explanation than I am going to give here.
"Programming on the main" is programming your loco on your layout without using a special isolated or separate programming track, and[FONT=Verdana, Tahoma, Arial, Trebuchet MS, sans-serif, Georgia, Courier, Times New Roman, serif] "Programming on the Main" only allows limited programming and access to all the decoder info. All of [/FONT]which is fine if you want to keep programming or access to decoder info very simple and basic. The other problem with "Programming on the Main" is that you have to remove all the locos from the layout otherwise all your locos end up with the same info in their decoders, including the same address.
"Programming on the Programming Track" takes place on a dedicated programming track which can either be a separate piece of track from the layout or a short, loco length of track in the main layout track-work that can be electrically isolated from the rest of the layout by means of gaps and a DPDT switch. Programming on the programming track allows you to access far more information from the decoder, it allows you to programme far more info into the decoder and because you are insulated from the rest of the layout you don't have to remove all the other locos from the layout.
Now to NCE in particular.....NCE has two basic systems....The Powercab system and the Powerpro system......simply put...the Powercab is a complete, lower-power starter set that allows you at a very good price, to quickly get your layout up and running in DCC..BUT because its a lower-amp power system it will only run2-3 locos at the same time on a moderate size layout like Tonys or mine...it won't run 4,5,6,7,8,9 sound-equipped locos on a layout or power a big club layout....but it can be upgraded to do that simply by adding a 5 amp or 10 amp booster. More on that in a minute. What the regular Powercab system does allow is both "Programming on the Main" and " Programming on the Programming Track" WITHOUT a dedicated, separate, electrically-isolated programming track! The Why doesn't matter at this point.
The Powepro system is a slightly more complex system with much more power and is what you want if you have a huge basement empire or are using it to power a large club layout with lots of locos. The Powerpro allows you to "Programme on the Main" but it REQUIRES a separate electrically isolated programming track to access "Program on the Programming Track".
Our problem the other night was that Tony had turned his Powercab into a Powerpro by adding the booster, and since he didn't have a dedicated isolated programming track he only had access to "programming on the Main" which gave us limited information and abilities to programme the decoder. By having Tony disconnect his power-booster, we reverted his system to a Powercab which allowed us to use "Program on the Programming track" so we were able to see and fix the problem on that particular loco.
My advice would be that unless you already have a massive layout or are looking at running more than 3-4 locos at the same time start with just the Powercab system...it will give you eveything you need...and then if you decide you need more power to enlarge your layout or run more locos its a simple upgrade bt buying a power booster.