This most likely is NOT MorphOS issue but more experienced Powermac owners may shed some light on this.

Sometimes, when I power the computer it sounds 'chime' but does not proceed to boot. I can't hear that distinct sound when HDD starts-up, if you know what I mean. Also, the keyboard is 'frozen'. It may take a few tries to get it working.

As I said, it occures sometimes, but it is a more worrying trend now that it has happened a few times in the past week or so. What to look for? From what I've read at other forums, it can be anything really - faulty HDD, RAM, power supply, expansion card, etc.

try reseting pmu

Thanks for suggestions.

Ok, I tried many things, including resetting PMU. It turns out that the battery is causing the problem. It gives voltage reading of 1.7 when it should be around 3.6 volts. Somehow, I managed to boot successfully after reseating it and will replace it tomorrow.

It's worth checking your PRAM battery if you have a Powermac. With shelf life of 4 years, it may need attention. Go with high capacity lithium as replacement.