I have an Athearn F59PHI (DCC + Tsunami sound equipped) that stalls constantly on my track, particularly in turnouts. After the first stall or two, when I push it, the loco runs through the rest of the layout at a faster speed, without stalling, but it does not respond to any throttle settings.
Now, before you assume it's because of dirty track or unjuiced frogs, I have another Athearn F59PHI, also with DCC sound, that runs just fine and doesn't stall. The only apparent difference between the two are the roadname that's painted on.
I took to opening up the problem loco and couldn't see any issues with contact. Is there something I should look for? I also opened up the trucks to access the gears and there's more grease in that thing than the stove of a roadside diner, could that be a factor?