Lenovo 3821, 3822, 3719, 3823 manual Memory problems

Memory problems

vFollow the suggested actions in the order in which they are listed in the Action column until the problem is solved.

vSee Chapter 8, “Parts Listing, TD200x Machine Types 3719, 3821, 3822, and 3823,” on page 237 to determine which components are customer replaceable units (CRU) and which components are field replaceable units (FRU).

vIf an action step is preceded by “(Trained service technician only),” that step must be performed only by a trained service technician.

Symptom	Action
The amount of system memory	1.	Make sure that:
that is displayed is less than the
		v No error LEDs are lit on the operator information panel or on the DIMM.
amount of installed physical
		v Memory mirroring does not account for the discrepancy.
memory.
		v The memory modules are seated correctly.
		v You have installed the correct type of memory.
		v If you changed the memory, you updated the memory configuration in the
		Setup utility.
		v All banks of memory are enabled. The server might have automatically
		disabled a memory bank when it detected a problem, or a memory bank
		might have been manually disabled.
	2.	Check the POST event log for DIMM error messages:
		v If a DIMM was disabled by a system-management interrupt (SMI), replace
		the DIMM.
		v If a DIMM was disabled by the user or by POST, run the Setup utility and
		enable the DIMM.
	3.	Run memory diagnostics (see “Running the diagnostic programs” on page 90).
	4.	Make sure that there is no memory mismatch when the server is at the
		minimum memory configuration (two 512 MB DIMMs; see the information about
		the minimum required configuration on page “Solving undetermined problems”
		on page 124).
	5.	Add one pair of DIMMs at a time, making sure that the DIMMs in each pair are
		matching.
	6.	Reseat the DIMMs.
	7.	Replace the components in step 6, one at a time, in the order shown, restarting
		the server each time.
Multiple rows of DIMMs in a	1.	Reseat the DIMMs; then, restart the server.
branch are identified as failing.
	2.	Replace the lowest-numbered DIMMs with identical known good DIMMs; then,
		restart the server. Repeat as necessary. If the failures continue after all
		identified pairs are replaced, go to step4.
	3.	Return the removed DIMMs, one pair at a time, to their original connectors,
		restarting the server after each pair, until a pair fails. Replace each DIMM in the
		failed pair with an identical known good DIMM, restarting the server after you
		reinstall each DIMM. Replace the failed DIMM. Repeat step 3 until you have
		tested all removed DIMMs.
	4.	(Trained service technician only) Replace the system board.

68ThinkServer TD200x Types 3719, 3821, 3822, and 3823: Hardware Maintenance Manual