Power Supply

Last night I installed a motherboard in a friends mini-tower.
That was easy but I can’t figure out why I’m not getting any power to the CD-Rom drive,the main power-switch and the fan on the power supply is not working.
My friend said when he bought the tower and power supply the tech tested the power and it worked but he also said the fan was not hooked up.
What troubleshooting methods are required.