I5 stock fan not working

[sadduck]

Hi everyone,
Yesterday i finished my new build and everything was working fine. However today i find that when my PC is stood up the CPU fan doesn't spin, it stutters, but won't spin. The CPU in question is a i5 2500 k (stock speed and fan)However if i turn the PC onto it's side it will spin. I have unwrapped the wire from around the heatsink and loosely tied them away so there is nothing stopping the fans from moving. Yet no matter what i do i just can't get the fan to start when the PC is stood up which it was doing fine yesterday and this morning. I can start the fan with the PC led down then stand the PC up whilst it running and the fan continues to work. Is it a dodgy heatsink or have i done something wrong.
I've also tried plugging the heatsink into my chassis fan power slot to see if it was the motherboard but even then it just stutters.

 

[aaab]

Sounds like a bad fan. I would just go buy a new cooler, since you have the 2500k you can overclock!

 

[sadduck]

I'm not planning on overclocking it yet and theirs no that much room to fit a new cooler. All these aftermarket coolers are huge and the stock one just fits next to my ram. Looks like i'll have to return it and get new one.

 

[bumnut53]

I'm not planning on overclocking it yet and theirs no that much room to fit a new cooler. All these aftermarket coolers are huge and the stock one just fits next to my ram. Looks like i'll have to return it and get new one.

Only high performance coolers are huge, you will be able to fine one that fits.

 

[TheBigTroll]

ex hyper 212. just mount it horizontally so that it doesn't bock your ram

 

[InvalidError]

Sounds like a bad fan.

It could also be that the motherboard's PWM controller is set too low for the fan to start. This happens with some fans when the fan controller is set to Quiet in BIOS.

On my 212+, the fan speed goes as low as 600RPM and if I stop the fan with my fingers at that point, it does not start again on its own until CPU temperature gets hot enough to make it jump to 800RPM then ramp back down to 600RPM.

So the fan may be perfectly fine but just not receiving power long enough to kickstart them at low core temperatures.

 

[sadduck]

I don't think that's the reason as i plugged it direct into the chassis fan power slot with is 3 pin only and should make the fan run at full speed which it does indeed when led down just not when it's stood up.
Now the problem i git is that i accidentally bent 2 pins in the top left corner of the socket when removing it, just slightly bent. I've manage to get them quite straight again with a knitting needle but i don't know if it will be good enough. Do very slightly bent pins really matter?

 

[InvalidError]

Do very slightly bent pins really matter?

As long as they remain correctly aligned with LGA pads and can apply sufficient contact force to correctly pass signal/power, it will be fine.