Q: Is there a place where I can get a Power Book G4 serviced?

Here are a few links I found that may be of value in seeking G4 PB service and repair. 

http://shop.wegenermedia.com/index.php?main_page=index&cPath=59&zenid=ba10e0feb9 c07e5af2bcd282dd25b8e2

http://www.iresq.com/macbook-repair/powerbook-g4-aluminum.html

https://www.powerbookmedic.com/mac-service.php

http://www.macservice.com/powerbookg4.html

http://www.welovemacs.com/posepa1.html

Obviously depends on what country you are in.

Obsolete products are those that were discontinued more than seven years ago. Apple has discontinued all hardware service for obsolete products with no exceptions. Service providers cannot order parts for obsolete products. These include ALL G4 and G5 models.

http://support.apple.com/kb/HT1752?viewlocale=en_US