Description Spare part number
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For use in models with Windows 8 Professional 688852-601
System board for use only with computer models equipped with an Intel HM75 chipset that include an Intel
Core i5 or i3 processor
 
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For use in models without Windows 8 685761-001
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For use in models with Windows 8 Standard 685761-501
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For use in models with Windows 8 Professional 685761-601
System board for use only with computer models equipped with an Intel HM70 chipset that include an Intel
Pentium or Celeron processor
 
●
For use in models without Windows 8 685768-001
●
For use in models with Windows 8 Standard 685768-501
●
For use in models with Windows 8 Professional 685768-601
Thermal pad (for use with all models) 651046-001
Before removing the system board, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the
computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and
then unplugging the AC adapter from the computer.
4. Remove the battery (see 
Battery on page 36).
5. Remove the following components:
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WLAN module (see 
WLAN module on page 45)
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Hard drive (see 
Hard drive on page 49)
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Keyboard (see 
Keyboard on page 54)
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Top cover (see 
Top cover on page 57)
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Speakers (see 
Speakers on page 65)
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USB board (see 
USB board on page 67)
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Power connector cable (see 
Power connector cable on page 69)
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Display assembly (see 
Display assembly on page 71)
6. Disconnect the display cable from the system board (see 
Display assembly on page 71).
NOTE: When replacing the system board, be sure that the following components are removed from the
defective system board and installed on the replacement system board:
●
Memory module (see 
Memory module on page 47)
●
RTC battery (see 
RTC battery on page 51)
ENWW Component replacement procedures 81