3-36
Compaq Professional Workstation AP550 Maintenance and Service Guide
Table 3-9
DIMM Guidelines
continued
Guideline Comment
DIMMs must be installed in pairs, alternating
between the two SDRAM expansion boards.
Compaq recommends populating the lower DIMM slot
on each SDRAM board first, then populating the
upper DIMM slots to upgrade memory.
RIMMs and DIMMs can not be mixed on the same
system board.
The system will not boot if RIMMs and DIMMs are
mixed on the same board.
CRIMMs (Continuity RIMM) must populate the empty
RIMM sockets (XMM2 and XMM4).
If CRIMMs are not installed in the empty RIMM
sockets, the system will not boot.
When replacing the workstation access panel, the
stabilizer card (attached to the access panel) must
engage the SDRAM expansion boards to balance the
boards.
CAUTION:
The above guidelines must be followed when installing SDRAM expansion boards,
or the workstation will not function.
CAUTION:
RIMM sockets have gold metal contacts. When upgrading memory, it is important to
use SDRAM expansion boards with gold metal contacts (not tin-lead) to prevent corrosion
and/or oxidation resulting from having incompatible metals in contact with each other.
CAUTION:
When handling a memory module, be careful not to touch any of the contacts. Doing
so may damage the module.
DIMM Removal
To remove a DIMM memory module:
1. Perform the steps in the “Service Preparations” section as previously shown.
CAUTION:
Before removing the workstation access panel, ensure that the workstation is
turned off, all cables are disconnected from the back of the workstation, and the power cord is
disconnected from the grounded AC outlet.
2. Lay the chassis on its side and remove the workstation access panel.
WARNING:
DIMMs can reach a temperature of 212
°
F (100
°
C) in a matter of minutes. Caution
should be exercised whenever removing or replacing these components.