Motherboard (system board)- For use with models that have discrete graphics subsystems and 14. ... 0-inch displays. P/N: 599522-001 Laptop motherboard for HP ProBook 4421s Series Motherboard 599522-001 IMPORTANT TECH NOTE ... of LCD display , Two memory, DVD driver, Network connection, Voice, Mouse, Keyboard, Dial, USB, SD connector, PC, 3.3V COMS battery ...