Intermittent issue where it will not power up or powers down.
Visual inspection, stripped down and removal of all plug in parts. Need to perform some hardware reset actions that will not affect the data.
Whole system blasted to remove debris and dust.
Parts removed and introduced one by one to see if a component was causing the issue.
No sign of physical damage or malfunction of parts. Got it to power up once, all plug in parts (HDD, Optical Drive and RAM) seem ok.
CMOS battery charge is with expected values.
The system did come back all though fairly slow, performed several resets and the system came back up.
Left to soak test and during this the system then closed down without reason. This was one of the exiting symptoms.
Needs an internal clean, need to source an air compressor
New motherboard required.