MacFixIt.com has written a roundup piece regarding the lower RAM slot failure present on some PowerBook G4 and iBook laptops.

The article suggests a battery of tests and workarounds that can be performed, the first being to re-seat and swapping RAM modules, later switching the RAM modules between slots.

Hardware problems are also mentioned, the roundup mentioning logic board failure symptons such as the laptop not booting and generally emitting three short beeps in lieu of a startup chime and the sleep LED flashing periodically. Apple has admitted to hardware flaws covered by its "Memory Slot Repair Extension Program", which only covers 15" 1.67 GHz PowerBook G4 laptops with serial numbers in the range of W8503xxxxxx through W8518xxxxxx.

For the full article as well as its relating article and additional fixes to try, click here.

If you've had similar problems or discovered fixes and workarounds, let us know.