no more chime sound on my PB

Jeffery Jones2 has the solution.  Turns out “15-inch PowerBooks are susceptible to a failure of one of the memory slots. Loss of the startup chime is a possible symptom. Check the amount of RAM reported in “About This Mac”. Does it agree with the amount installed?

There was a Repair Extension Program (now expired) for this issue. See http://support.apple.com/kb/HT2164 for more info.”