On Sun, 30 Oct 2016, Jon Elson wrote: You never know until you try. Anyway, the Alphaserver 4100 has four midsize muffin fans and I found them trivial to take apart and trivial to replace the bearings which were a standard off the shelf part. It was easier to fix the fan than it was to replace them since DEC had a custom fan with a speed sensor built in that proved impossible for me to find. It changes from model to model and generation to generation. -- Richard Loken VE6BSV, Systems Programmer - VMS : "...underneath those Athabasca University : tuques we wear, our Athabasca, Alberta Canada : heads are naked!" ** rlloken at telus.net ** : - Arthur Black