On older Macs, the video card is built into the logicboard, but on newer systems the video card is either a PCI or AGP card. Power Supply Power supplies are most often found mounted at the rear of the case. They can range from 150 to over 200 watts depending on anticipated use. Most have output voltage of 5-12 volts. Power supplies contain fans that move air across the components to keep them cool.
Fans are a common failure point.
Do not attempt to repair a faulty power supply. Even units that have been off for sometime can hold a dangerous charge. PRAM Parameter Random Access Memory . It keeps settings for your clock, keyboard, monitor etc. RAM Random access memory is the key to a properly functioning computer system.