Thanks 
I didn't get to spend much time on it yesterday but a couple of notable things happened. The chime came back (intermittently) so the speaker is working fine.
On the not-so-good side, at one stage the hard disk started powering down and back up again (like when its not getting enough power). I hit the reset switch and it stayed powered on. It may have been a glitch of some kind but if it happens again I wonder if it might point to the 300w PSU not being up to the task. I also ran MacTest Pro on it and it failed some of the Video tests in the logic board section. It may have been running the wrong tests I'll have to double-check as it was late when I was doing this. Everything else passed OK and video is working fine (passed the AHT tests).
I ran the test again and I think the logic board test may be a little flaky. If I deselect all the logic board tests and run each video test individually they all pass. But if I try to run all of the video tests it fails on the second one (Video DAC Read/Write).
I didn't get to spend much time on it yesterday but a couple of notable things happened. The chime came back (intermittently) so the speaker is working fine.
On the not-so-good side, at one stage the hard disk started powering down and back up again (like when its not getting enough power). I hit the reset switch and it stayed powered on. It may have been a glitch of some kind but if it happens again I wonder if it might point to the 300w PSU not being up to the task. I also ran MacTest Pro on it and it failed some of the Video tests in the logic board section. It may have been running the wrong tests I'll have to double-check as it was late when I was doing this. Everything else passed OK and video is working fine (passed the AHT tests).
I ran the test again and I think the logic board test may be a little flaky. If I deselect all the logic board tests and run each video test individually they all pass. But if I try to run all of the video tests it fails on the second one (Video DAC Read/Write).