Replacing the motherboard

Replacing the motherboard consists of the following procedures:

The following table describes the main components of the motherboard and indicates whether you can replace them.

Components	Description	Is it field replaceable?
Components	Description	F720	F740	F760
CPU	21164A DEC Alpha® chip operating at 400 Mhz for F720 and F740, and at 600 Mhz for F760.	no	no	no
J6	Onboard FC-AL port	no	no	no
J45	Console/Diagnostic port	no	no	no
J1	Onboard Ethernet port	no	no	no
J26	Onboard differential fast wide SCSI port for external tape drive	no	no	no
CPU fan	The CPU fan is mounted on the CPU heat sink and must be operating any time the filer is powered on. See Replacing the CPU fan for replacement instructions.	yes	yes	yes
SDRAM DIMMs	The SDRAM DIMMs are installed into four DIMM slots (J27, J28, J29, and J30). See Replacing SDRAM DIMMs on the motherboard for replacement instructions.	yes	yes	yes
Lithium battery	The 3.3V lithium battery provides backup power to the real-time clock and motherboard firmware configuration NVRAM. The lithium battery on the motherboard differs from the lithium batteries on the NVRAM adapter. You cannot interchange batteries for the motherboard and the NVRAM adapter. See Removing the motherboard lithium battery for replacement instructions.	yes	yes	yes

The following figures show the three variations of the F700 series motherboard:

To remove the motherboard, complete the following steps.

Step	Action
1	Open the PCB carrier. Follow the procedure in Opening the PCB carrier.
2	Using a 3/16 socket wrench, remove all the screwlocks connected to the PCB carrier.
3	Remove the expansion adapters on the motherboard. Follow Steps 3 through 5 of Removing an existing expansion adapter.
4	Remove the SDRAM DIMMs. Follow Steps 2 through 5 of Removing an SDRAM DIMM.
5	Using a #2 Phillips screwdriver, remove the 11 screws holding the motherboard to the PCB carrier.
6	Lift the motherboard and slide it out of the PCB carrier.

To install the motherboard, complete the following steps.

Step	Action
1	Slide the replacement motherboard into the PCB carrier and, using a #2 Phillips screwdriver, secure the motherboard to the PCB carrier with the 11 screws.
2	Reinstall all SDRAM DIMMs. Follow Steps 1 through 4 of Installing an SDRAM DIMM.
3	Reinstall all expansion adapters into the expansion slots on the motherboard. Follow the procedure for Installing an expansion adapter.
4	Using a 3/16 socket wrench, connect all the screwlocks to the PCB carrier.
5	Paste the MAC (Media Access Control) address label provided with the replacement motherboard on the PCB carrier, as shown.
6	Proceed to Closing the PCB carrier.