I don't recall any lights showing through the vent on mine when I had one, although it's been a long time since I had it. A lot of chips do have a led of some sort on it, so it wouldn't surprise me if it's that.
The shutting down while playing sounds like a laser protection fix. 70002 is either a v12 or 13. V12 consoles have a fault that can cause the laser to burn out, a few of the fixes that are normally installed with chips on that model, shut the console down as soon as a problem is detected to protect the laser. So if it's a v12, then it's probably that.