Posting this on my father's behalf to try and diagnose what's up with his machine:
The machine is around 5/6 years old, I can't remember the exact spec and has recently been suffering from the following problems when turning the machine on:
The machine initally starts to power up, then just seems to loose power. It requires a forceful turn off (10s on power button) to be able to start the power up process again. Normally this process needs to be repeated until the machine 'warms up'. Once it's been running for a while you can shut it down and start it up with out problems.
Sometimes the machine will start up with certain devices disabled. E.g. the mouse won't be working one time, restarting the machine and the graphics card might be on the blink, yet a 3rd time all might be working fine.
All seems a bit strange, if anyone has any incline as to what might be the problem it'd be great to hear.