Heh, yeah no fun and no one would know why!
Well, this app reliably hard powers off my IIx, and if I know what I'm doing, that should be because the v2PowerOff bit of the VIA2 data register B is being set to 0, causing the power supply to shut off. Which should provide a reasonable diagnostic for your SE/30. If running this app causes that line to go low, but regular shutdown doesn't, then it's reasonable to assume regular shutdown isn't toggling that pin. If this app doesn't cause that line to go low, then I'm not sure...
For those following along at home, I recommend not running this. Not all machines have a 2nd VIA. Some machines have other stuff at that location and what's "safe" (as much as hard powering off your machine is safe...) for this class of machines, may be even worse for other machines. It's intended for diagnostic purposes only, and even then only on IIx & SE/30's...
Well, this app reliably hard powers off my IIx, and if I know what I'm doing, that should be because the v2PowerOff bit of the VIA2 data register B is being set to 0, causing the power supply to shut off. Which should provide a reasonable diagnostic for your SE/30. If running this app causes that line to go low, but regular shutdown doesn't, then it's reasonable to assume regular shutdown isn't toggling that pin. If this app doesn't cause that line to go low, then I'm not sure...
For those following along at home, I recommend not running this. Not all machines have a 2nd VIA. Some machines have other stuff at that location and what's "safe" (as much as hard powering off your machine is safe...) for this class of machines, may be even worse for other machines. It's intended for diagnostic purposes only, and even then only on IIx & SE/30's...