I would tend up look upstream of the ignition switch

I (respectfully) disagree. I think that he should be looking upstream of the constant-power line for the fault.

He was right to be confused, we really are saying the opposite thing.

Your statement that the player draws most of its current from the ignition-switched line is, I believe, based on other brands of car stereos. In other brands of car stereos, the constant power line really is only used for the clock memory. But in the Rio Car player, it fully powers the unit, including CPU, disk drives, and everything (if you awaken it from standby with the ignition off). So the yellow wire really does need a lot of juice.

I know that the Mark2 (not 2a) players could get their juice from the orange wire if they had no other choice. But on the 2a players, even this is not possible and the orange wire is merely an "ignition sense" wire, and does not need a lot of current. That wire simply detects for the presence of 12v, it doesn't need to draw all of its current from that wire.

Rob, I respect your opinion and your intelligence, and I am willing to be proven wrong on this point. Hugo, can you jump in here and clarify this? It's important that we all understand how it works.