The operating manual for the Icom PS-125 power supply states
an order of sequence for power up/down. It says supply on
first, then load. Then load off/supply off in that order.

When I asked Icom Tech support why, they said it was to make
sure no glitches got to the load (in this case a 756ProII.)

When I pull the "Big Switch", everything goes off. Anyone
ever heard of the PS-125 blowing its load? (Oops, you know
what I mean).

Don K6LTS
email at QRZ