1.Turnoffthecomputeranddisconnectallpowercordsfromelectricaloutlets.
2.Removethecomputercover.See“Removingthecomputercover”onpage32.
3.Laythecomputeronitssideforeasieraccesstothesystemboard.
4.Locatetheheatsinkandfanassembly.See“Locatingpartsonthesystemboard”onpage11.
5.Disconnecttheheatsinkandfanassemblycablefromthemicroprocessorfanconnectoronthesystem
board.See“Locatingpartsonthesystemboard”onpage11.
6.Followthissequencetoremovethefourscrewsthatsecuretheheatsinkandfanassemblytothe
systemboard:
a.Partiallyremovescrew1,thenfullyremovescrew2,andthenfullyremovescrew1.
b.Partiallyremovescrew3,thenfullyremovescrew4,andthenfullyremovescrew3.
Note:Carefullyremovethefourscrewsfromthesystemboardtoavoidanypossibledamagetothe
systemboard.Thefourscrewscannotberemovedfromtheheatsinkandfanassembly.
Figure31.Removingtheheatsinkandfanassembly
7.Liftthefailingheatsinkandfanassemblyoffthesystemboard.
Notes:
a.Youmighthavetogentlytwisttheheatsinkandfanassemblytofreeitfromthemicroprocessor .
b.Donottouchthethermalgreasewhilehandlingtheheatsinkandfanassembly.
8.Positionthenewheatsinkandfanassemblyonthesystemboardsothatthefourscrewsarealigned
withtheholesonthesystemboard.
Note:Positionthenewheatsinkandfanassemblysothattheheatsinkandfanassemblycableis
towardthemicroprocessorfanconnectoronthesystemboard.
9.Followthefollowingsequencetoinstallthefourscrewstosecurethenewheatsinkandfanassembly .
Donotover-tightenthescrews.
a.Partiallytightenscrew1,thenfullytightenscrew2,andthenfullytightenscrew1.
48ThinkCentreUserGuide