self-service CRUs depending on product design might include memory modules, adapter cards, harddisk drives, and optical drives.• Optional-service CRUs: These CRUs are isolated parts within the computer and are concealed by anaccess panel that is typically secured by more than two screws. Once the access panel is removed, thespecific CRU is visible.Number FRU description Self-service CRU Optional-service CRU1 Wi-Fi card No Yes2 System board No No3 Microprocessor No No4 Memory module Yes No5 Heat sink and fan assembly Yes No6 Coin-cell battery Yes No7 Power supply assembly No Yes8 Computer handle No No9 Power button board No Yes10 Optical drive Yes No11 Chassis No No12 Card reader No No13 Front audio and USB assembly No No14 Front bezel Yes No15 Front Wi-Fi antenna No No16 Thermal sensor No No17 Power cord Yes No18 Primary storage drive Yes No19 Secondary storage drive Yes No20 PCI Express card Yes No21 Rear Wi-Fi antenna No No22 Rear Wi-Fi antenna cover No No23 Computer cover Yes NoFor detailed FRU information, such as the FRU part numbers and supported computer models, go to:http:/www.lenovo.com/serviceparts-lookupChapter 2. Product overview 33