I have 4 PS3 engines currently and a 44ton switcher on order.
All Railking:
PS3 0-6-0
PS3 2-8-2
PS3 Dash 8
PS3 ES44
I run my trains in conventional via MTH Z-1000s.
Very occasionally and with no obvious "order" (only happens at random and again very occasionally a PS3 engine will start up with sound instantly upon track power being applied. Here is a break down of what happens
1) Put engine on track
2) Apply power
3) Engine lights and sound immediately come on, similar to PS2. No other features are functional. If I attempt to move the engine before the "required" 20 second or so wait, it will immediately go dark and silent
4) If power is reapplied, the engine will respond normally and sit silent with the headlight on until it is charged up. It will run as intended.
Again, happens very occasionally. Do I have a board/cap issue here? I've seen it discussed before and seen possible indication of a bad "chain file" (whatever that may be). I've also contact MTH and have had techs say clean the track but otherwise we don't have a clue. Of course, clean track, etc makes no difference.
I also saw an engine being demoed at the LHS do the exact same thing. I would take a video but it can be hard to catch.