No, the power supply from the C650 will not work on your 7600. For example, the 7600 needs a 3.3V line, and the C650 supply does not have a 3.3V line.
The C650 power supply is usable in the IIcx, IIci, IIvi, IIvx, Q700, C650, Q650, and 7100.
You can also use it on the bench to boot up a IIsi or (IIRC) 6100, but, obviously, the PS will not fit in the case of those two machines.
It is possible to adapt a standard ATX power supply made for PCs to use in the 7600, but it would be challenging to find a long narrow one that will fit in the 7600 case.