My nearest Apple service center wasn’t able to work on my PowerBook before my trip next week, so I decided to try to fix the memory problem myself. Fortunately I found a screwdriver that will open the PowerBook at Radio Shack (in the Kronus Electronics Screwdriver Set, part #64-2967).
I was able to get it open easily, remove both DIMMs and reinstall them. After opening it twice and swapping the DIMMs, I see it still reports only 512M and System Profiler always says the lower slot is empty no matter which DIMM is in it. I also notice there’s no startup chime although sound works after I boot, which leads me to believe I have a problem with the motherboard.
I notice some strange messages in my system log:
Jan 11 15:48:42 localhost kernel: AppleRS232Serial: 0 0 AppleRS232Serial::start - returning false early, Connector or machine incorrect
Jan 11 15:48:44 localhost kernel: Sound assertion "0 == inputDataMuxOSNumber" failed in "AppleOnboardAudio/AppleOnboardAudio.cpp" at line 3309 goto Exit
Jan 11 15:48:47 localhost kernel: Sound assertion "0 == mLineInDetectIntProvider" failed in "AppleOnboardAudio/KeyLargoPlatform.cpp" at line 1252 goto Exit
Jan 11 15:48:47 localhost kernel: Sound assertion "1" failed in "AppleOnboardAudio/PlatformInterface.cpp" at line 143 goto handler
Jan 11 15:48:47 localhost kernel: Sound assertion "0 == inputDataMuxOSNumber" failed in "AppleOnboardAudio/AppleOnboardAudio.cpp" at line 3309 goto Exit
UPDATE: I ran the hardware test and the logic board passed, but it shows a memory error detected at startup. Looking at Apple’s discussion forums, there seems to be a common problem with the lower DIMM slot in 15″ PowerBooks going bad. It requires a logic board swap.