Noisey cooling fans

[my2rotties]

I have a lighting unit with built in fans. One of them is so loud I can't hear myself think. Is there a way to make it quiet or do I just try to find a replacement for it? It has a rattle and it will get more quiet for a short period but never whisper quiet. Usually it just rattles and hums incessantly.

Can cleaning it or doing something to it help matters or is it loud because it is shot?

Thanks in advance.