I recently bought a new to me Mac Pro 5,1 and on opening it has more fuzz in it than a 70s porno movie. I dont think it has ever been opened. I gave it a quick blast with the air compressor - from about 2 feet as I was afraid I could damage it. Getting the hoover on it bothers me because of the static but then again I'm worried too much compressed air could damage it or drive the dirt deeper in. The CPUs literally had a beard each - maybe it's the ZZ-Top model - massive tufts of fluff growing out the fans. Amazingly the temps seem reasonable although I noticed in Mac fan Control app that the Intake fan is constantly at zero and marked in red. I have to get this dust off before I try fitting more ram - I did blow off the worst of it but it could really do with a more thorough clean - any advice? or do you think maybe the dirt is now holding it together - as my buddy calls it "load bearing dirt".
Unplug your System first .
Remove as many parts from the System as you feel comfortable with and blast everything with a compressor at 60 PSI from 6 inches away .
Observe ESD safety precautions , if necessary (with the memory , video cards, etc.)
Especially blast the PSU from both sides and all the heatsinks .
If you remove your CPU Tray for cleaning , observe ESD safety precautions and clean both interconnects . Perform this cleaning operation last, after you are done cleaning anything else . You never want any contaminants on an interconnect . Never touch an interconnect , either .
Before starting up the System again , let the System dry for an hour (if no moisture has been observed) , three hours (if light spray has been observed) or overnight (if liquid water drops have been observed) during cleaning . All compressors will shoot some amount of water out (even if you do not see it) - it is natural .
I've been doing this for years without any problem and my Builds are squeaky clean inside .
Never use a vacuum cleaner or hair drier to clean electronics . You will ZAP something .
Also, get a filter for the front of your cMP - they are available from TransIntl : http://www.transintl.com/mac*************ischmutz-air-filter.html
I would also visually verify all your case fans are spinning . Case fans rarely fail with Apple Professional Desktops - I've only seen three or four failures in the last 15 years .
I once talked with an user who had a PC server in continuous service for two decades . It was full of dust to such an extent it actually became a part of the chassis . He shut down the System because he was alarmed by it and cleaned it out . The System died right then and there . He waited too long :-(