I need to replace my chipset fan but have no idea what kind of fan I need. I have a Dell Dimension 4550. I'm not sure what size I need and the like. I tried looking it up in my users guide, but was unable to find any usefull information. All I found out is that it has a J1F1 Power connection. Do I have to buy a fan from Dell because it's a weird size or could pretty much any size fan work? Any help would be appreciated.