Just to give you the additional option of replacing the fan.
That fan is a frameless 74mm +12V fan made by ARX.
The part number is FS1280-AP184C.
A brand new one is 15.80 RMB (=US$2.50) in China.
There is an used one in the ebay UK link below and is US$29 (the fan is located in Jackson, Michigan, United States and so you can save some mailing cost.)
These fans are not blue though.