Motherboard • Replacing
the Motherboard • Replacing
SDRAM DIMMs on the Motherboard • Replacing the Lithium Battery on
the Motherboard • Replacing the CPU Fan
This section describes the procedures for removing and installing the PowerVault 720N,
740N, and 760N motherboards. The three motherboards are shown here:
- 720N motherboard
 |
| 1 |
Fan |
| 2 |
Lithium battery |
| 3 |
SDRAM DIMMs |
|
- 740N motherboard
 |
| 1 |
Fan |
| 2 |
Lithium battery |
| 3 |
SDRAM DIMMs |
|
- 760N motherboard
 |
| 1 |
Fan |
| 2 |
Lithium battery |
| 3 |
SDRAM DIMMs |
|
This section also describes the procedures for replacing or upgrading the following
units on the motherboard:
- synchronous random-access memory (SDRAM) dual in-line memory modules (DIMM)s for the
system memory
- CPU fan
- lithium battery
The motherboard must be replaced for onboard components that are not field replaceable.
The following components are not field replaceable:
- CPU — 21164A DEC Alpha chip operating at 400 MHz for 720N and 740N and at 600 MHz
for 760N
- J6 — Onboard FC-AL port
- J45 — Console/Diagnostic port
- J1 — Onboard Ethernet port
- J26 — Onboard Differential Fast Wide SCSI port for external tape drive
The following components are field replaceable:
- CPU cooler fan — The CPU fan is mounted on the CPU heat sink and must be operating
any time the filer is powered on. Refer to Replacing the
CPU Fan for replacement instructions.
- SDRAM DIMMs — The SDRAM DIMMs are installed into four DIMM slots (J27, J28, J29,
and J30). The total memory for each filer is 256 MB for the 720N, 512 MB for the 740N, and
1 GB for the 760N.
- Lithium battery — The motherboard uses one 3.3-volt lithium battery to provide
backup power to the real-time clock and motherboard firmware configuration NVRAM. The
lithium battery on the motherboard differs from the batteries on the NVRAM adapter. The
batteries for the motherboard and the NVRAM adapter cannot be interchanged.
How to Remove the Motherboard
To remove the motherboard, perform the following steps.
 |
CAUTION: Always use the halt command to perform a proper shutdown. |
- Shut down the filer and turn off power to the filer.
- Lift up the clip lock and unplug the AC power cord from the filer power supplies.
- Put on the antistatic wrist strap and attach the grounding leash to an acceptable
grounding unit.
- Disconnect all cables connected to the ports on the back panel of the filer.
- Using a 3/16-inch nut driver, remove all the screwlocks of all the onboard components.
- To open the PCB carrier, follow Steps 4 and 5 of the procedure described in Opening the PCB Carrier.
- To remove the PCB carrier from the chassis, follow Steps 2 and 3 of the procedure
described in Removing the PCB Carrier.
- Using a #0 or #1 Phillips-head screwdriver, remove all adapters from all expansion slots
on the motherboard. For information about this procedure, refer to How to Remove an Existing
Expansion Adapter.
- To remove all SDRAM DIMMs, follow Steps 5 through 8 of the procedure described in How to Remove an SDRAM DIMM.
- Using a #2 Phillips-head screwdriver, remove the 11 screws holding the motherboard to
the PCB carrier, lift the motherboard, and slide it out of the PCB carrier.
- Proceed to How to Install the Motherboard.
To install the replacement motherboard, perform the following steps:
- Slide the replacement motherboard into the PCB carrier and, using a #2 Phillips-head
screwdriver, secure the motherboard to the PCB carrier with the 11 screws.
- To reinstall all SDRAM DIMMs, follow Steps 1 through 4 of the procedure described in How to Install an SDRAM DIMM.
- Using a #0 or #1 Phillips-head screwdriver, reinstall all adapters in the expansion
slots on the motherboard. For information about this procedure, refer to How to Install an Expansion Adapter.
- To reinstall the PCB carrier in the chassis and close it, follow the procedure described
in Closing the PCB Carrier.
- Paste the Media Access Control (MAC) address label provided with the replacement board
on the PCB carrier, as shown.
 |
| 1 |
Paste MAC address label here |
|
- Using a 3/16-inch nut driver, replace all the screwlocks of all the onboard components.
- Reconnect all the cables to the ports on the back panel of the filer.
- Plug the AC power cord into the AC power cord receptacle on the power supply and secure
it with the clip lock.
- Turn on the filer.
This section provides the procedures for adding or replacing the SDRAM DIMMs on the
motherboard.
The memory requirements for the PowerVault 720N, 740N, and 760N filers are as follows.
| Filer |
Required memory configuration |
| 720N |
3.3-volt, unbuffered, 4x64 MB SDRAM DIMMs |
| 740N |
3.3-volt, unbuffered, 4x128 MB SDRAM DIMMs |
| 760N |
3.3-volt, unbuffered, 4x256 MB SDRAM DIMMs |
|
CAUTION: All DIMMs must be obtained from Dell. Do not use unapproved DIMMs.
|
The following figure illustrates a typical SDRAM DIMM.
To remove an SDRAM DIMM, perform the following steps.
|
CAUTION: Always use the halt command to perform a proper shutdown. |
- Shut down the filer and turn off power to the filer.
- Lift up the clip lock and unplug the AC power cord from the filer power supplies.
- Put on the antistatic wrist strap and attach the grounding leash to an acceptable
grounding unit.
- To open the PCB carrier, follow Steps 4 and 5 of the procedure described in Opening the PCB Carrier.
- Locate the DIMM that you want to remove.
- Push apart the latches on either side of the DIMM to release the DIMM from its slot, as
shown.
- Pull the DIMM out of the slot.
- Set the DIMM aside in an antistatic bag.
- Proceed to How to Install an SDRAM DIMM.
To install a replacement SDRAM DIMM, perform the following steps:
- Locate the DIMM slot for the DIMM you are installing.
- Hold the DIMM by its top corners to avoid damaging the components and turn the DIMM so
that the locator notches on the edge connector are away from the lithium battery.
|
CAUTION: Visually inspect the DIMM to verify that it is
evenly aligned and fully inserted into the slot; otherwise, the edge connector on the DIMM
does not make complete contact with the slot. |
- Insert the DIMM straight into the slot. The DIMM fits tightly in the slot, but should go
in easily. If not, realign the DIMM with the slot and try again.
- Push carefully but firmly on the top edge of the DIMM until the latches snap into place.
- Push in the PCB carrier and tighten the eight thumbscrews on the back panel.
- Plug the AC power cord into the AC power cord receptacle on the power supply and secure
it with the clip lock.
- Turn on the filer.
This section provides the procedures for adding or replacing the 3.3-volt lithium
battery on the motherboard. The following figure shows the location of the lithium
battery.
 |
| 1 |
Lithium battery |
| 2 |
SDRAM DIMMs |
|
To remove the motherboard lithium battery, perform the following steps.
|
CAUTION: Always use the halt command to perform a proper shutdown. |
- Shut down the filer and turn off power to the filer.
- Lift up the clip lock and unplug the AC power cord from the filer power supplies.
- Put on the antistatic wrist strap and attach the grounding leash to an acceptable
grounding unit.
- To open the PCB carrier, follow Steps 4 and 5 of the procedure described in Opening the PCB Carrier.
- Lift up the battery toward the open side of the battery holder, as shown in the
following figure.
- Dispose of the old battery according to the manufacturer's instructions that come with
the replacement battery.
- Proceed to How to Install the
Motherboard Lithium Battery.
To install a replacement motherboard lithium battery, perform the following steps.
 |
WARNING: There is danger of a new battery exploding if it is replaced
incorrectly. Replace the battery only with the same or equivalent type recommended by the
manufacturer. Dispose of used batteries according to the manufacturer's instructions. |
- Turn the battery so that the positive side is up (marked with a "+").
- Push the battery through the open side of the battery holder so that it sits flush
inside the battery holder.
- Push in the PCB carrier and tighten the eight thumbscrews on the back panel.
- Plug the AC power cord into the AC power cord receptacle on the power supply and secure
it with the clip lock.
- Turn on the filer.
This section provides the procedures for replacing the CPU fan on the motherboard.
To remove the CPU fan, perform the following steps.
|
CAUTION: Always use the halt command to perform a proper shutdown. |
- Shut down the filer and turn off power to the filer.
- Lift up the clip lock and unplug the AC power cord from the filer power supplies.
- Put on the antistatic wrist strap and attach the grounding leash to an acceptable
grounding unit.
- To open the PCB carrier, follow Steps 4 and 5 of the procedure described in Opening the PCB Carrier.
- Unplug the P3 fan power connector from the J3 connector on the motherboard, as shown in
the following figure.
 |
| 1 |
P3 connector |
| 2 |
J3 connector |
| 3 |
CPU heat sink |
|
- Remove the four screws that fasten the fan to the CPU heat sink.
- Lift the CPU fan from the CPU heat sink.
- Set the CPU fan aside.
- Proceed to How to Install a CPU Fan.
To install a replacement CPU fan, perform the following steps:
- Orient the replacement fan so that the label side is toward the heat sink.
 |
| 1 |
Label side toward heat sink |
|
|
CAUTION: Do not over tighten the fan screws; otherwise, you might damage the
heat sink and its bond to the CPU. |
- Replace the four screws to secure the CPU fan to the heat sink.
- Plug the P3 CPU fan cable connector into the J3 connector on the motherboard.
The connectors are keyed so that they can fit together only one way.
- Push in the PCB carrier and tighten the eight thumbscrews on the back panel.
- Plug the AC power cord into the AC power cord receptacle on the power supply and secure
it with the clip lock.
- Turn on the filer.
