Question : Problem: HD & monitor will not power up

Very occasionally in the past my HD & Monitor would not power up after a shut down but after poking and prodding plugs/cards etc I always got the PC to run. This time however no matter what I do I can't get any life out of it.
The power supply is ok, the green led comes "ON" on the monitor (flashing), the HD tries to run but there are no beeps. I disconnected the monitor signal cable and immediately the warning sign pops up on the monitor so there's nothing wrong with the monitor. I read in the archive of a similar problem where the CPU sink had flashed and caused motherboard failure but in my case the PC has always fired up afterwards (except for this time) which couldn't happen if the CPU/mainboard had burnt.
I did find my CPU fan was running slow but have now cleaned and oiled it and is now running at full speed.
I'll be happy to hear from anyone with experience of this problem, I'm getting desparate!

Answer : Problem: HD & monitor will not power up

PAQed, with points refunded (100)
ee_ai_construct - CS Mod