CPU Sockets Explained: LGA vs PGA and Installation for the A+ Exam
The socket is the mechanical and electrical interface between processor and motherboard. The A+ exam tests the socket types, correct installation, and what goes wrong. LGA, PGA and BGA Type Pins on Used by Replaceable LGA — land grid array The socket Intel desktop, AMD AM5 Yes PGA — pin grid array The processor AMD AM4 and earlier Yes BGA — ball grid array Soldered Laptops, mobile devices No LGA puts the contacts in the socket as spring-loaded pads, and the processor has flat gold lands on its underside. Bend a pin and you have damaged the motherboard, not the CPU. PGA puts the pins on the processor and the holes in the socket. Bend a pin here and you have damaged the CPU. That reversal is the whole exam point, and it has a practical consequence: with LGA, treat the socket as the fragile part and never touch the contact array; with PGA, treat the processor as fragile and always set it down on its top surface. BGA is soldered directly to the board. Not user-replaceable, wh...