It has always worked just fine, and in almost all ways except this still does. *snip* cpu temperature starts to rise quite rapidly to the high 50s, and the fan gets very loud indeed. I don't know how far it would go, because one of us closes the browser fairly soon when this happens, and eventually the temperature falls to below 50.
*snip* It does do it when rendering some pdfs. Particularly, it did it with a graphics intensive pdf of some sort.
***Another machine is an old 754, and it does not happen on it.***
Hi Peter,
At the wish of pointing out the obvious, if you use moving parts for cooling, those moving parts will need to be serviced (ie: cleaned/repaired/replaced) at some point. Like a car, you may get away with not doing, but you may not.
The first thing I'd do with an overheating problem that happens when the machine is under stress, independent of software, is look at the cooling. Dust the fans and heat sink grooves out first, make sure the case has its cover on and that any exhausts have decent clearance - see if that solves the problem (it has for me many times). Remove the dust from the rest of the machine if so, this will only gather back at the fan otherwise
Replace/repair any bits that aren't working properly - if you can measure individual temps and see that something like the GPU is getting super-toasty, this might include reseating the heat sink with a bit of thermal paste - some of the coolers those blighters are very heavy and moving the machine a few times might have hurt the bond - again, something that's saved me replacing components before now.
I'd say a swift look at the cooling has solved such problems for me "quite often", so it's worth having a look.
Also, consider liquid cooling if you buy new kit, as it doesn't get this problem so much, obviously. Good luck.