Chrisau and Bruce.........
Cleaning the dust and gunk out of the box, off the fan blades, etc isn't the problem.
I did that about a week ago and do it about every six months.
(I haven't gone inside the power box to clean that fan, but it seems to be running ok)
All the fan speeds seem to be running at about the same speed as before, but of course, the smart-fan on my CPU is running faster than before.
I feel that "something" is failing.......(the MOBO???), and overheating.
Are there any further checks?
TIA