I have one of these locos, identifiable by the unusual, mirror-like finish on the frame, that had a pretty annoying pickup problem that I couldn't track down for the longest time. Long story short, this one was caused by a contact strip not seating tight enough in the slot on the frame half, beneath the fuel tank casting. The frame slot is simply too wide for the contact strip and they may be too loose without some kind of modification. On my loco, the contact strip on one side was somewhat mangled where it seats into this slot and that one was making contact just fine, as the mangling caused the contact strip to seat quite tightly. However, the other one that was causing problems was not mangled, was very loose in the slot and instead had evidence of some kind of glue on it (not helping with conductivity, I'm sure!). I removed the silicone-like glue blob and then added a solder blob to the bottom of the contact strip. The strip then seated tightly in the slot and the pickup problem went away. I may have purchased this loco second-hand, so I'm not sure if the mangled strip and/or the glue blob were from the factory or if they were modification efforts by a previous owner. At any rate, if your VO-1000 is having pickup issues that the usual fixes don't resolve, you may want to look into this. Not sure if the later versions of this loco might have similar issues.
