Dell OptiPlex 755 - Manual (Page 36)

1. Loosen the captive screw on each side of the heat sink assembly.
2. Rotate the heat sink assembly upward, and remove the assembly from the computer.
Lay the heat sink down on its top.
System Board Components
CAUTION: Despite having a plastic shield, the heat sink assembly may be very hot during normal operation. Be sure that it has had sufficient time
to cool before you touch it.
1 heat sink assembly
2 captive screw housing (2)
1 internal speaker (INT_SPKR) 12 intrusion switch connector (INTRUDER)
2 processor connector (CPU) 13 battery socket (BATTERY)
3 processor power connector (12VPOWER) 14 PCI Express x16 connector (SLOT1)
4 memory module connectors (DIMM_1, DIMM_2, DIMM_3, DIMM_4) 15 PCI connector (SLOT2)
5 password jumper (PSWD) 16 PCI connector (SLOT3)
6 SATA connectors (SATA0, SATA1, SATA2) 17 riser connector (uses PCI-E port/SLOT1 and PCI port/SLOT2)