Have to hand start case fan

[Techfruit]

Hello all, for the past few months I've had to hand-start one of my case fans. once it starts it keeps going until I turn off or restart my system, programs like speedfan show that it's spinning at normal RPM before I start it and some times it takes considerably longer to start than others.

After some web searching I've come up with either it's busted or my PSU is, it's plugged directly into my PSU and recently I've noticed the center of the fan is hot to the touch and it's progressively getting harder to start. so I have a few questions starting with, how could I go about telling if the fan itself is the problem or if it's a more serious concern like my PSU? and if it is the fan, how do I go about finding out what size it is to replace it? there are no markings on the fan itself and it came stock in the case when I purchased this prebuilt computer.

 

[Paul NZ]

Remove the fan take it into a shop. They'll tell you the size

 

[synphul]

From everything you've described it sounds like the fan is shot. Having to flick it to get it going, the hub (where the fan motor is located) is hot to the touch etc. Worn bearings, loss of lubrication which is likely only made worse by running hot and 'cooking' whatever lube is left. You should be able to give a light flip to one of the fan blades when the pc is off and it should spin freely several rotations with little to no effort. If you have to flick it hard or really push on the fan blade and as soon as you stop the fan freezes up immediately, the bearings are bad.

You can either take the fan to a shop or look at a fan size chart for common sizes. This page shows the overall fan frame size and distance between screw holes from 40mm fans up to 120mm fans.
https://www.quietpc.com/faq/27

If the fan hole spacing is wider or the frame is larger then it's likely 140mm, other sizes above that are less common and the next most common size is 200mm which is pretty noticeable. There's a photo partway down on this page (note the page is using very large photos, may be slow to load on a slower connection) comparing a 200mm to a 140mm fan.
http://www.rage3d.com/board/showthread.php?t=34003341