IBM 7383 Installation And Service Manual page 175

Table 21. Memory problems and actions (continued)
v Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
v If an action step is preceded by "(Trained technician only)", that step must be performed only by a trained
technician.
v Go to the IBM support website at http://www.ibm.com/supportportal to check for technical information, hints,
tips, and new device drivers or to submit a request for information.
Symptom
Multiple DIMMs in a channel
are identified as failing.
Action
Note: Each time you install or remove a DIMM, you must disconnect the server
from the power source; then, wait 10 seconds before restarting the server.
1. Reseat the DIMMs; then, restart the server.
2. Remove the highest-numbered DIMM of those that are identified and replace it
with an identical known good DIMM; then, restart the server. Repeat as
necessary. If the failures continue after all identified DIMMs are replaced, go to
step 4.
3. Return the removed DIMMs, one at a time, to their original connectors,
restarting the server after each DIMM, until a DIMM fails. Replace each failing
DIMM with an identical known good DIMM, restarting the server after each
DIMM replacement. Repeat step 3 until you have tested all removed DIMMs.
4. Replace the highest-numbered DIMM of those identified; then, restart the
server. Repeat as necessary.
5. Reverse the DIMMs between the channels (of the same microprocessor), and
then restart the server. If the problem is related to a DIMM, replace the failing
DIMM.
6. (Trained technician only) Install the failing DIMM into a DIMM connector for
microprocessor 2 (if installed) to verify that the problem is not the
microprocessor or the DIMM connector.
7. (Trained technician only) Replace the system board.
Chapter 4. Troubleshooting
157