Thanks,
As its a wet and miserable day here in the UK, I have stripped down and rebuilt the maxx, replacing its PSU at the same time.
I think the monitor has failed now, as I briefly see the BIOS Post test screen then it fades out. The monitor would probably be the hardest bit to replace?
No sound from the machine after cleaning and brushing the contacts and IOboard. Am I correct in that the speaker connector pin connects to the right hand side of the IO board?
To elimate the monitor I am going to find a VGA cable and connect it to an alternative screen.