This repair guide covers several aspects of take apart to replace components:
https://www.ifixit.com/Device/PowerBook_G4_Aluminum_17%22
They offer a 'troubleshooting guide', that says little about replacement of cables
and suggest several issues could relate to a defective logic board...
https://www.ifixit.com/Wiki/PowerBook_G4_Aluminum_17%22_Troubleshooting
You may have to contact an Apple Authorized Service Provider where a Specialist
can inspect the failed component cabling, or if you replace the cable yourself in a
process of elimination, it may be the answer. All cables in the way of any access
points inside the computer can be suspect; several of them including drive cables,
should be replaced if the machine has ever been opened before your visit inside.
At times, even the slightest damages, almost undetectable, can result in failure.
Note there is a PDF service article (download unless preview is supplied) in the
search result from google; the original service guides from Apple are best if you
can find a source and use it to troubleshoot & repair your computer, hard to find.
https://www.google.com/?gws_rd=ssl#q=PowerBook+G4+zif+cable+troubleshooting
In this article, reading though the Cached version, I see a warning that may apply:
•Zero Insertion Force Connectors
Zero insertion force (ZIF) connectors are used in several locations in the computer.
Important:The locking bar on the ZIF connector is extremely fragile and is not intended to
separate from the connector. When releasing a bar, use extreme care and a restrained
light pressure to move the bar only slightly.
Warning: If a locking bar breaks, you will need to replace the board!
{In my search, it appears as download or in cached view link; you can dissect the
link below to find the original www. website _17.pdf within the middle of it to see
if the download version can be downloaded for offline personal use; if the online
version appears to offer some helpful purpose in resolving issues for you.}
cached service guide:
http://webcache.googleusercontent.com/search?q=cache:MfdoM7QU67gJ:www.macbook-fr .com/IMG/pdf/PowerBook_17.pdf+&cd=1&hl=en&ct=clnk&gl=us
Any broken connector or loose solder joint, or flexed circuitry can be suspect.
Good luck & happy computing! 🙂