ALL PC's and most laptops still use a generic set of standard voltages, basically 3, 5, and 12 volt lines. 5 and 12 being typically for peripherals and 3 volt being pretty much only for the motherboard and IC's themselves. Do a search on good (and here in the forums) for modifying an ATX power supply into a bench suppy. Then you can use banana jacks as outputs and multimeter leads as contacts and you can apply a voltage to just about anything you want. As far as testing the motherboard fan connector, plug in a known working fan, that's a good test. A multimeter may not always provide reliable results because fans on motherboards are sometimes fed PWM power, rather than a steady DC.