If you can't boot up at all to get to the System Profiler, simply remove all the sticks of RAM. Then take one stick and put it in the RAM slot, and boot it up. If it boots up correctly, that RAM is good. Power it down, take out that RAM stick, put in another, boot up, etc. Eventually you'll find the offending RAM module. Eric Buczynski On Jan 28, 2007, at 2:56 AM, g4- request at listserver.themacintoshguy.com wrote: > ubject: Re: [G4] G4 will not boot up after addung a 128 HD > To: "A place to discuss Apple's G4 computers." > <g4 at listserver.themacintoshguy.com> > Message-ID: > <944d273d0701272355k1f2b5ceib84eccb177f67661 at mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > It means the RAM in slot 3/J24 is malfunctioning, more info about > you mac > world help... "G4" could be anything from Power Mac G4 PCI Graphics > to Mac > Mini G4. > > -brett