Dell Precision WorkStation 420 Service Manual page 45

2. If necessary, remove any RIMMs that occupy sockets in which you plan to install the RIMMs.
NOTES: If you are not installing a replacement RIMM at this time, you MUST remove the remaining RIMM in the pair and install a pair
of continuity modules (CRIMM).
When operating with a single pair of RIMMs, they MUST occupy sockets RIMMB-1 and RIMMA-2, with CRIMMs installed in RIMMB-3
and RIMMA-4.
3. Install the RIMMs.
a. Locate the plastic securing clips at each end of the socket (see
b. Press the clips outward until they snap open.
c. Press the RIMM straight into the slot running down the center of the socket until the securing tabs snap into place around the ends
of the RIMM.
Figure 31. RIMM Installation
4. Replace the computer cover, and reconnect your computer and peripherals to their electrical outlets and turn them on.
NOTE: After you remove and replace the cover, the chassis intrusion detector causes the following message to appear on the
screen at the next system start-up:
ALERT! Cover was previously removed.
The system detects that the new memory does not match the existing system configuration information and generates the following
message:
The amount of system memory has changed.
Strike the F1 key to continue, F2 to run the setup utility
5. Press <F2> to enter System Setup, and check the value for System Memory.
The system should have already changed the value of System Memory to reflect the newly installed memory. Verify the new total. If it is
correct, skip to step 7.
6. If the memory total is incorrect, turn off and disconnect your computer and peripherals from their electrical outlets. Remove the computer
cover, rotate the power supply, and check the installed RIMMs to make sure that they are seated properly in their sockets. Then repeat
3, 4, and 5.
7. Reset the chassis intrusion detector by changing Chassis Intrusion to Enabled or Enabled-Silent.
NOTE: If a setup password has been assigned by someone else, contact your network administrator for information on resetting
the chassis intrusion detector.
8. When the System Memory total is correct, press <Esc> to exit System Setup.
9. Run the Dell Diagnostics to verify that the RIMMs are operating properly.
Microprocessor/Heat Sink Assembly
To replace a microprocessor, perform the following steps.
NOTE: Dell recommends that only a technically knowledgeable person perform this procedure.
CAUTION: Before you remove the computer cover, see
Figure 31).
1 Securing clips (2)
2 Notches (2)
"Precautionary Measures."
steps