Startup/Hard Drive problems with iBook G4

[andrewhowat]

My iBook G4, bought about two and a half years ago, recently developed a very serious problem. Occasionally, on startup, I get a blank screen, then a flashing folder icon with a question mark/Mac OS icon. This happens erratically. Sometimes the computer starts up just fine.

The first few times it happened, I did an Apple Hardware test, and got the following error code under the 'mass storage' heading.

2STF/2/3: ATA - 100 ata - 6 - Master

I rang Apple, even though the iBook is out of its 2 year warranty (by a couple of months naturally). They suggested it was a hard drive fault.

Foolishly trusting them more than I should have, I went out and bought a new hard drive (with identical spec) and replaced it myself. During the repair I noticed one of the screw fixings (a little metal loop) on the bottom shield had sheared off, but thought nothing of it (I find it hard to believe this has any relevance).

I replaced the drive, reinstalled everything, including all the old files, and the computer worked fine... for about three days.

The computer started to hang for a few minutes every so often when asked to do simple tasks (open an application, save a document, etc.) and we'd get stuck with the colour wheel. The application's didn't crash, they just worked very slowly, and it wasn't confined to any particular app.

Eventually we started getting the same erratic startup error. Hardware test reports no errors, as does Techtool Deluxe (even when I run every single test, including a surface scan). I opened up the iBook again to check all the cables and screws, but everything looks perfectly intact to me.

Has anyone encountered anything like this before? I am utterly stumped, and not nearly wealthy enough to have Apple fix it (especially if it's something as serious and costly as a logic board problem or something). I heard a rumour there is such a thing as a 'memory distribution' problem that might cause these symptoms, but google doesn't turn up anything under that description.

Please help! My Mac is dying!