Servicing work on SMPS units

[Faringdon]

Hi,
I just had to service some returned  750W Offline (SMPS) Power supplies  that have two 24V, 0.18A cooling fans in them.

**Removing dust with air:
Some  have lots of dust over them, and  due to all the components and daughter boards, its not possible to  get rid of all the dust with just an ESD brush. How can you blow dust away without causing ESD harm to components?

**Awkward_to_get_to screws:
Some screws are on the PCB, and due to  tall components crowded round the screw hole, you have  to “stick” the screw  to the screwdriver head with blu tak so that you can position the screw into the screw hole. Is there a better way than with blu tak?

**Fan Rasping noise:
On one unit, the fan is making a racket,  kind of rasping. It’s a 24V, 0.18A BLDC fan. Outwardly the fan looks fine, but is it worth taking it apart?...or is it likely to be a cracked bearing , and hence a new fan is needed?

[jpanhalt]

Does this mean you figured out how to screw them down to their boxes?

[thm_w]

I prefer a vacuum cleaner for dust, but compressed air works too if you don't care about mess:
https://www.eevblog.com/forum/chat/does-air-compressor-produce-esd/
https://www.eevblog.com/forum/beginners/vacuum-cleaner-on-pcbs-disaster/

You asked similar screw question here already: https://www.eevblog.com/forum/manufacture/blu-tak-used-in-metal-cased-psu-assembly/

Replace the fan, don't bother opening it up or cleaning it.