If your iBook G4 Charger Plug Cord breaks off or frays enough to quit working properly, all is not lost. You can fix it if you can solder wires back together. Here's how.
Step 1: Cut the Cord
You'll need to cut off the cord. First make sure you've unplugged the charger from the wall.
Step 2: Cut the Plastic Barrel Apart
Next you need to saw through the plastic barrel without damaging the circuit board or wires inside. I used a saw-blade steak knife. I small hack saw blade would work too. Cut back approximately 1/2 inch from the barrel light. As you saw, just go deep enough to cut through the thickness of the plastic as you rotate the barrel. Use short, light strokes. When you've rotated it 360 degrees, you're finished cutting.
Step 3: Remove the End of the Barrel and Rubber Sleeve
Slip the small end of the plastic barrel off of the rubber "plug" beneath. Now carefully cut through the rubber plug or sleeve with a small knife or scissors and discard it. The metal housing underneath appears to be a cord retainer originally designed to prevent pulling the wires loose from the circuit board in the plug. You should have at least 1/8th to 1/4 inch of useable wire to solder this back together. If you don't then you'll have to remove the old wires and solder new pigtails to the circuit board to continue. I've repaired two of these successfully without having to remove the old wires from the circuit board.
Step 4: Prep and Solder the Wires Back Together
Assuming you had at least 1/8th to 1/4 inch of wire left on the plug to solder to, prepare the wires for tinning with your soldering iron. Clean away any non-metallic cordage, trim the ends to 1/4", twist them tight and tin the ends with solder. Now prep the ends of the the wires coming from the charger. Strip back 1/2 inch of the the plastic insulation and carefully remove it without damaging the fragile wire mesh beneath. Then peel away this wire mesh surrounding the 1st, insulated wire and twist it together to form your 2nd wire. Make sure to remove the fiber cord when doing this. Clean and tin the ends with solder. Get some rubber insulating electrician's tape. Solder the gray, insulated wires back together. Cut some thin strips of this tape and insulate this soldered wire right up to the plug. Now solder the 2nd wires back together and using thin strips of the tape, insulate this wire from the first. Some people would skip this step as unnecessary, but you cannot be too careful to insulate one wire from the other. Now wrap the rubber tape around the end of the plug and back along the insulated, soldered wires.
Step 5: Protect the New Connections From Breaking Again
Some people would say to use shrink tubing or glue to protect the wires from breaking again. I have a simple solution, I think. It looks a bit weird, but works just fine. Start by folding the wire up alongside itself to where it lays alongside the plastic barrel. Tape it in place with a small strip of rubber tape. Don't go up too far alongside the barrel or the wire won't allow a flush fit of the plug into the laptop. Once it is "just right," finish your rubber tape job.
Step 6: Better Than New
That's it! Your plug should work if you soldered things back together properly. You will now have created a side-load on the plug that won't bend and break the fragile wires. Some might think this will put more load on the fragile male fitting that slips into the socket on the laptop. If you prefer not to have this side load, just run the wire back along itself and tape over the second loop to where you have a plug with an end-load. Frankly, I think the side-load plug creates a tighter connection that is not as prone to wiggling around.