v Follow the suggested actions in the order in which they are listed in the Action column until the problem issolved.v If an action step is preceded by “(Trained technician only),” that step must be performed only by a trainedtechnician.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 ActionMultiple DIMMs in a channelare identified as failing.Note: Each time you install or remove a DIMM, you must disconnect the serverfrom 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 itwith an identical known good DIMM; then, restart the server. Repeat asnecessary. If the failures continue after all identified DIMMs are replaced, go tostep 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 failingDIMM with an identical known good DIMM, restarting the server after eachDIMM replacement. Repeat step 3 until you have tested all removed DIMMs.4. Replace the highest-numbered DIMM of those identified; then, restart theserver. Repeat as necessary.5. Reverse the DIMMs between the channels (of the same microprocessor), andthen restart the server. If the problem is related to a DIMM, replace the failingDIMM.6. (Trained technician only) Install the failing DIMM into a DIMM connector formicroprocessor 2 (if installed) to verify that the problem is not themicroprocessor or the DIMM connector.7. (Trained technician only) Replace the system board.Microprocessor problemsUse this information to solve microprocessor problems.v Follow the suggested actions in the order in which they are listed in the Action column until the problem issolved.v If an action step is preceded by “(Trained technician only),” that step must be performed only by a trainedtechnician.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 ActionThe server goes directly to thePOST Event Viewer when it isturned on.1. Correct any errors that are indicated by the light path diagnostics LEDs (see“Light path diagnostics” on page 134).2. Make sure that the server supports all the microprocessors and that themicroprocessors match in speed and cache size. To view the microprocessorinformation, run the Setup utility and select System Information > SystemSummary > Processor Details.3. (Trained technician only) Make sure that microprocessor 1 is seated correctly.4. (Trained technician only) Remove microprocessor 2 and restart the server.5. Replace the following components one at a time, in the order shown, restartingthe server each time:a. (Trained technician only) Microprocessorb. (Trained technician only) System boardChapter 4. Troubleshooting 161
