For my Mac Pro 1.1, I've installed 12GB of Memory however one of my Memory Riser Cards has 4 GB, but is only acknowledging them as 2 GB. On the same Card I see a single "Red Light." I can only assume this to be an error. What could this mean and what do I need to do to resolve it? Worse case scenario I have replace the Memory Riser Card.
Thank you in Advance.
Mac Pro, Mac OS X (10.7.5), OWC RAM
Try reseating the RAM on the problem riser.
Inspect the RAM slots and contact on the sticks for abnormalities
Try to find the bad stick. WIth one bad stick both sticks in that pair will not show up.
Remove one pair and see it that resolves the light and if the show up. Repeat with other pair.
Try reseating the RAM on the problem riser.
Inspect the RAM slots and contact on the sticks for abnormalities
Try to find the bad stick. WIth one bad stick both sticks in that pair will not show up.
Remove one pair and see it that resolves the light and if the show up. Repeat with other pair.
Your Mac Pro with Xeon processor has Error-correcting memory, so it can determine when modules are bad. The red light usually indicates a bad RAM module.
If seen as having ANY problem at Startup (from a cold start, not ReStart) the slot will be declared "empty" and the module will NOT be used.
The memory modules themselves (especially the FBDIMMs used in 2006 through 2008 models) are thousands of times more likely to be the source of the problem than the riser-card.
Modules seen as half their correct size are BAD (or not the correct DIMMs for your Mac Pro, which has stringent requirements for timing, Heatsink size, and temperature monitoring chips).
Be sure to test new modules by themselves before checking with existing modules for "plays nice with others" -- a separate issue.
Thank you. This was very helpful. Through a process of elimination I was able to figure that one of the memory sticks was causing the problem. Interesting enough it was brand new from OWC. Thank goodness for the warranty.
OWC FBDIMMs have a history of issues, higher price and not running as cool - there are lots of good reliable FBDIMMs out there that work, new Amazon, server pulls on ebay.
I have 8x2GB of these:
http://smile.amazon.com/BUFFERED-PC2-5300-FB-DIMM-Arch-Memory/dp/B002ORUUAC/
Red Light on Memory Riser Card
