Well, the rest of the X58 boards have no fan unless you count the E759. So my guess is it is not needed, just unplug the fan. If you feel safer with one get a 50mm fan and ziptie it on there.

PM sent, thanks Matt
 
will just the fan be sent or the whole black casing with it as well?

Its the entire enclosure, I made the request to have a replacement sent. For now its fine to run it without the fan.

I have the same motherboard, and eVGA was kind enough to send me a replacement too.  One additional thing I discovered in the process is the elusive cause of the rattle (yes this has been a known issue for some small but real percentage of e758 owners).  At least in my case, it's the little power wires for the fan.  They enter the fan housing and cross to the other side.  Some type of clip or glue or channel or something (I forget, it's been a few months since I was doing this) was there to keep the wires from ever interfering with the fan blades.  But that constraint relaxed over time, maybe the wires worked loose with temperature change or vibration.  So it ends up being the fan's own power wires slightly interfering with the fan blades that produces the rattle.  Funny, mine only does it between certain ranges of Northbridge fan RPM too, so by intentionally running the board hotter or cooler I can often avoid it :D
 
Anyway, I mention this because you may be able to save your original fan as a backup unit when you're replacing it with the new one -- or you might want to do something to make sure the new one's wires really stay clear of the fan over the long run.

The Northbridge fan on my E758 recently died.  Can someone send me a replacement or know where I can purchase one?

I'm running it without the fan right now and it's about 60 - 65c on idle.  Do you know of any good fans that would work with the e758?

My fan started making noise last November, but was quiet for the most part for the last 3 months...until today.  I investigated a bit, and found that it wasn't the power cord getting in the way, but the fan was tilting to one side, so that the underside of the blades were hitting one of the supports where the fan screws into the little black housing it's inside.
 
EDIT: I'd post a link to the forum thread where I put up pictures of my findings, but seems I'm underqualified to do links yet on here.

loveha

Well, the rest of the X58 boards have no fan unless you count the E759. So my guess is it is not needed, just unplug the fan. If you feel safer with one get a 50mm fan and ziptie it on there.

 
MY 760 does not have it but my 762 has a small fan on the NB , maybe it's related to the nf200 chips ??  

My NB fan has been noisy on and off for months, and pretty much every time I cold start my PC lately it's noisy.  Has anyone found a reliable solution other than strapping a 50mm fan to the heat sink?  I tried submitting this as a ticket but there's no way I'm going to RMA my board over a fan.