Dell OptiPlex 990 (Early 2011) - Manual (Page 25)

Heat Sink
9
Removing the Heat Sink
1. Follow the procedures in Before Working Inside Your Computer .
2. Remove the cover .
3. Remove the front bezel .
4. Remove the drive cage .
5. Disconnect the heat sink/fan assembly cable from the system board.
6. Press the release lever down and move it outward to release the fan
retention hook that secures it.
7. Raise the heat sink/fan assembly.
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