Final update provided 10 apr 14 as a public service:
Nothing wrong with the engine except maybe the smoke and volume pots were in the wrong locations. Problem was trying to add an 11th engine to the DCS Commander console which can only store 10 engines in memory. Oddly enough, you can assign any address # from 1 to 99 but the total quantity of PS2/3's that can be added to the Commander console memory is limited to 10. There are also apparently two different versions of the users manual. One version says "can store up to 10 engines" and another version -- in error -- says "can store up to 99 engines". If this sounds confusing, it is. Cost for the Commander console is about half of full DCS system but not worth it IMO when you consider the much greater advantages of full DCS.
OP:
I received a new RK PS3 GP7 diesel (30-20187-1) the other day that exhibits odd behavior and features. When I fired it up in conventional sound blasted out full as usual. So I turned it over and adjusted the volume down but no change. On a second attempt I adjusted the smoke output all the way down and then no volume??? Long story short, the smoke dial adjusts the volume and volume dial adjusts the smoke. Also could not get my DCS Commander (the console) to recognize or add the engine. Ok, so I checked to see if the DCS/DCC switch was set to DCC. But there's no switch -- anywhere. Huh?
Any help or suggestions appreciated. Thanks.