Kind of a strange one, although I may already have a hypothesis at least. Looking for some old iMac heads to confirm this. Was getting random crashes for quite some time now. Finally got around to running Memtest V 5.1 with all 4 slots filled, which Failed rather quickly.
Long story short: narrowed it down to slots 2 and 3 (both upper, but different physical modules on the logic board), as it refuses to boot with either or both of thse slots populated. Confirmed that Known-Good RAM units were used in slots 2 and 3 by the way.
When slots 0 and or 1 (or both) are populated, the system boots fine, Memtest passes No single SO-DIMMS have been found to be bad so far.
Tested my 2011 with RAM only in slot 2, then only in slot 3 and it boots fine, so I presume a 2010 should boot with RAM in slot 2 and or slot 3 also. *Please correct me if I am wrong, but I can't imagine why a 2010 would be different in this regard.
I'm surprised that slots 2 and 3 would go bad together since they part of different physical connectors. Unless somebody has some details on the memory controller for these logic boards that suggest otherwise?
For clarification, here is the RAM slot orientation on a 2010 (as far as I understand it):
*Upper Left: -Slot 2- ..... *Upper Right: -Slot 3- (Upper slots both left and right seem bad)
*Lower Left: -Slot 0- ..... *Lower Right: -Slot 1- (Lower slots both left and right seem fine)
Which begs the question: What could be inferred about the root cause of the problem here? Anyone ever seen concurrent RAM slot failures on disparate physical modules before? Thanks.
Long story short: narrowed it down to slots 2 and 3 (both upper, but different physical modules on the logic board), as it refuses to boot with either or both of thse slots populated. Confirmed that Known-Good RAM units were used in slots 2 and 3 by the way.
When slots 0 and or 1 (or both) are populated, the system boots fine, Memtest passes No single SO-DIMMS have been found to be bad so far.
Tested my 2011 with RAM only in slot 2, then only in slot 3 and it boots fine, so I presume a 2010 should boot with RAM in slot 2 and or slot 3 also. *Please correct me if I am wrong, but I can't imagine why a 2010 would be different in this regard.
I'm surprised that slots 2 and 3 would go bad together since they part of different physical connectors. Unless somebody has some details on the memory controller for these logic boards that suggest otherwise?
For clarification, here is the RAM slot orientation on a 2010 (as far as I understand it):
*Upper Left: -Slot 2- ..... *Upper Right: -Slot 3- (Upper slots both left and right seem bad)
*Lower Left: -Slot 0- ..... *Lower Right: -Slot 1- (Lower slots both left and right seem fine)
Which begs the question: What could be inferred about the root cause of the problem here? Anyone ever seen concurrent RAM slot failures on disparate physical modules before? Thanks.
