I just had the weirdest thing happen with my Mac Pro. I was playing with VMWare Fusion 2.0 last night and I couldn't understand why my Boot Camp Partition of Vista x64 was running soooo slowly (HDD was being accessed constantly), and it didn't get any better even after allocating more memory and virtual processors. By a chance discovery, I realised that my Mac was showing 2GB of memory rather than the 4GB I have installed. System profiler stated that all four memory slots on the lower riser card were empty.
I took the side panel off and discovered an LED lit on the lower riser card corresponding to DIMM2. I powered the system off and through a diagnostic process, discovered that the problem was the lower riser card socket, rather than the card itself (ie, swapped riser cards, lower one still not working). I prepared some information to call AppleCare but before I did, I decided as a last ditch effort, I'd reset the PMU by restarting and holding Cmd+Opt+P+R. Lo and behold, both memory riser cards were detected and my 4GB of memory was restored!
I have no idea what caused it, the only thing I could maybe attribute it to is possibly the 10.5.5 update but I couldn't say for sure.
Has anyone else ever had something like this happen before?
I took the side panel off and discovered an LED lit on the lower riser card corresponding to DIMM2. I powered the system off and through a diagnostic process, discovered that the problem was the lower riser card socket, rather than the card itself (ie, swapped riser cards, lower one still not working). I prepared some information to call AppleCare but before I did, I decided as a last ditch effort, I'd reset the PMU by restarting and holding Cmd+Opt+P+R. Lo and behold, both memory riser cards were detected and my 4GB of memory was restored!
I have no idea what caused it, the only thing I could maybe attribute it to is possibly the 10.5.5 update but I couldn't say for sure.
Has anyone else ever had something like this happen before?