The M7332 model number comes with two variants, the larger plug that fits both the PB1400 and others including the Pismo, and another variant with the smaller plug that fits newer models. The larger plug version is compatible with the PB1400, and I verified it is connected per the drawings by measurement. I refer to that document because it happens to have a drawing that correctly identifies ground and +24V connections, the tip being a no connection and the shell (as designated in the drawings and connected to a net called Adapter Sense) as a means to sense power adapter types, If I knew of a document for the PB1400 I would have used it. See figures 3, 4, 5 for what I mean by shell.
Excellent question. As I write this I have a PB1400 running and charging powered from 24V with that shell just floating, no connection, as an experiment. To avoid an unfortunate incident extreme care is advised making and verifying the connections. I am using a standard stereo Y cable that has no shell contact and is inserted so its shoulder does not touch the PB1400 shell sensing metal. Kind of looks like there is no sense circuit. But I cannot be sure if it has some kind of sense circuit and power manager programming to stop charging in the airline adapter powered configuration for some worse case running load situation, say with a maxed out PB1400 with accelerated CPU and disk and CDROM going simultaneously. I suspect just carefully hooking up a regulated 24VDC source will work fine but cannot guarantee it. Should future experimenters see a failure to charge while running, I conjecture that just adding a single 412k ohm resistor sense shell to gnd would make their jury rigged supply more equivalent to the Yo-Yo design. Also, it may be that the more commonly available value 390K would work also.
