LulzBot Taz 4 power supply PC cooling fan adapter
Check out the above link for details. Cliff Notes version: my factory power supply cooling fan died, so I retrofitted a standard desktop PC cooling fan to do the job. I like this new configuration better, but be careful if you decide to try it, because power supplies can be dangerous. I used an oven mitt and some aluminum foil to de-energize any capacitors that might hold a lingering charge prior to touching anything, and of course the first thing I did was unplug it from the wall.
If you print a PC fan adapter now (before your factory fan dies), you won’t need to make a cardboard adapter just to print the ABS adapter like I did.
I hope this is useful to someone! My Taz has been good to me, despite requiring a lot of TLC. They are excellent machines.