If the PSU is high quality, definitely worth it. If not send it to the landfill.
Fan replacement is a piece of cake but you need to be aware of the electrical danger that lurks inside of the PSU. I recently replaced a chirping exhaust fan inside my PSU. Clipped all wires and re-soldered with zero problems. One thing you want to do is make sure you have optimal airflow through the PSU. You should check the specs on the PSU fans and try to match or exceed them in airflow requirement. Heat is a critical factor in PSU power efficiecy.
The stock intake fan on my PSU is 92mm, 57cfm and the stock exhaust is 80mm, 39cfm. When my 80 went bad I replaced it with a super quiet PC Power and Cooling 27cfm fan that was a spare I had. Although I had no problems, it simply did not pull enough air out of the PSU for my liking. I ended up buying a replacement that exceeded the 39cfm stock fan. Now when running full out, the psu blasts air out the back. :thumbsup:
There is a row of vent holes on my PSU housing facing the cd-rom bay and if I would have left the low speed 27cfm fan in there, the intake fan on the PSU would have overcome the exhaust fan, the result being, air forced out through these holes and back into the case. Not what you want obviously. Just make sure to have matched fans for optimal heat removal. A PSU is one place you absolutely do not want heat accumulation.....
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