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iBook / PowerBook4,3 won't recognize 512MB SODIMMs


Well-known member
I have an iBook / PowerBook4,3 model A1005 (600MHz PPC) that I am trying to upgrade the RAM on. According to everymac.com it can take a single 512MB PC100 SODIMM. So I bought one and when I plugged it in, the iBook only reconized 256MB of additional RAM. So I thought that the stick might be mislabeled or bad, and I returned it.

I bought another stick from another vendor (Memory Masters) that specifically stated it supported my model of iBook. I just plugged it in and the iBook still only recognizes 256MB of additional RAM (total of 384MB).

System Profiler reports the SODIMM as 256MB, and it reports the iBook has a boot ROM version of 4.3.6f3.

Do I need a firmware update? Or is everymac.com just wrong about the RAM support?


Well-known member
... yes, the RAM needs to be double sided PC100/PC133. Also try to clean your RAM connector with electronic solvent spray; I've resurrected a few Powerbook RAM slots this way.