The Delta 1010 rack unit is not powered by the computer, it has it's own separate 9v AC 3.5A power adapter which should have been with everything when you bought it.
The Delta 1010 rack unit uses a "power on" signal from the PCI card, in order to turn on with the rest of the system, and if that is not working, I would first try to swap out the 25pin cable, if not, then the PCI card itself might be the problem for you.
If the rack unit does not power on, it could still be a capacitor issue causing the unit not to power on. The only way to find out would be to open up the rack unit and visually check the capacitors for bulging or oozing material (sometimes both).
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