One should perhaps not rule out that the internal video circuits are faulty in a way that a proper video output is not possible. Even file sharing via Ethernet would be difficult without a display.
With access to another Mac with a FireWire port, you may want to try target disk mode (Use target disk mode to share files between two Mac computers - Apple Support). The PowerBook G4 (there are several models, all with FireWire) could then be used as an external hard drive for that second computer. Should be OK without a working PowerBook display.
If nothing else works, you could remove the PowerBook's internal hard drive, and then connect it to another computer via a universal USB hard drive adapter (one example at http://www.newertech.com/products/usb3_universaldriveadap.php; similar devices can be found in computer shops).
One should perhaps not rule out that the internal video circuits are faulty in a way that a proper video output is not possible. Even file sharing via Ethernet would be difficult without a display.
With access to another Mac with a FireWire port, you may want to try target disk mode (Use target disk mode to share files between two Mac computers - Apple Support). The PowerBook G4 (there are several models, all with FireWire) could then be used as an external hard drive for that second computer. Should be OK without a working PowerBook display.
If nothing else works, you could remove the PowerBook's internal hard drive, and then connect it to another computer via a universal USB hard drive adapter (one example at http://www.newertech.com/products/usb3_universaldriveadap.php; similar devices can be found in computer shops).
Plug it into the TV, power it up and choose your TV's "input" to select the right HDMI input source (mine has two) - very straightforward
connecting Macs is easiest this way for me
How to connect with File Sharing on your Mac - Apple Support
My PowerBook G4 screen is broken
