Guidance on troubleshooting a non booting iBook
I´ve been given a broken iBook - G3 12 inches - 900 Mhz.
Upon close inspection i found out that someone sent it to the floor when it was plugged and charging. There was a dent in the case and the DC plug was bent and its inner connections broken.
I managed to repair the broken DC plug, now the battery charges properly; also i replaced the HDD which was broken, and also dealt with re-seating the graphic chip by means of a hair-dryer session.
Having the computer returned to life i managed to reinstall the OS (10.3.9) while it was wide open, but upon closing the case and putting (hopefully) everything back in its place, it won´t boot.
I have reopened it and, voila, it boots, so i´m guessing there´s a short somewhere.
Reading the different answers around here i´ve seen that the inner metal cover protection might be the culprit, as it could short if not properly placed. I´ll try this, but i´d like some extra advice of what else should i look for, in your opinion.
If you look at the front edge of the lower shielding, there is a little squarish flap of metal just to the right of the sleep light (assuming the shielding is right-side-up). This should be vertical, and should rest against the front of the frame when installed. However, it often gets flattened against the rest of the shielding, in which case it presses against the underside of the board when installed, and often causes a short and prevents the machine from powering on. That's the first thing I look for when I have a machine behaving as yours is.
Beyond that, the hairdryer/heat gun/etc. approach to the video issue is about as precise as driving in a thumbtack with a sledge hammer, and the issue almost always comes back in one form or another. It might last 5 minutes or a month, but believe me, unless you've had the chip professionally re-applied by someone with a very expensive rework machine, you're going to be seeing related issues again soon.
But hopefully it's just the shielding, in which case you'll have a usable machine until video-related problems start again.