CPU fan isn't spining but display is ok.

[Md z]

My PC configuration is

                                          Intel Core I5 3470S

                                         8GB Ram

                                         500 GB + 500 GB HDD

                                         250 Watt PSU

So my GT 730 2 GB GDDR5 GPU is dead. My brother left his PC because he lives in abroad . My brother PC has GT 630 1 GB DDR3 GPU. So I thought I should test his GPU . I plug in the GT 630 and start my computer . My PSU is low so i thought I should disconnect my 2nd HDD . So I unplug my 2nd HDD . then I start my computer . My computer start fine but a strange thing happen. I notice that my CPU fan is not spinning but the windows start normally. I check my CPU temperature and it was ok . The temperature was 44-46 °C . Then I again check the fan and the fan was't spinning but i can use the windows .After unpluging the GPU the CPU fan started to spinning. Why this happened? Is it safe ?

[EddE171]

Your motherboard is probably the issue. And it is safe but your performance will significantly drop if the temps get too high

[Analog]

14 minutes ago, Md z said:

My PC configuration is

                                          Intel Core I5 3470S

                                         8GB Ram

                                         500 GB + 500 GB HDD

                                         250 Watt PSU

So my GT 730 2 GB GDDR5 GPU is dead. My brother left his PC because he lives in abroad . My brother PC has GT 630 1 GB DDR3 GPU. So I thought I should test his GPU . I plug in the GT 630 and start my computer . My PSU is low so i thought I should disconnect my 2nd HDD . So I unplug my 2nd HDD . then I start my computer . My computer start fine but a strange thing happen. I notice that my CPU fan is not spinning but the windows start normally. I check my CPU temperature and it was ok . The temperature was 44-46 °C . Then I again check the fan and the fan was't spinning but i can use the windows . Why this happened? Is it safe ?

 

Most probably the fan has died. This is why it is not spinning. you can quickly check it though, by plugging it into a different fan header on the motherboard. It the fan starts spinning in another header, then it is this particular one has failed. If the fan doesn't operate regardless where it is plugged in, then it is the fan. If it is the fan, you can just by a replacement one or get a new cooler. It's up to you. 

 

The CPU cooler cannot operate properly without a fan. Yeah, it idles fine, as the heat output is enough that the cooler can passively cool it. Under load, however, the temperature will continue to rise until the CPU throttles severely in order to keep itself cool or eventually the computer will shut of due to overheating. 

[Md z]

18 hours ago, Analog said:

 

Most probably the fan has died. This is why it is not spinning. you can quickly check it though, by plugging it into a different fan header on the motherboard. It the fan starts spinning in another header, then it is this particular one has failed. If the fan doesn't operate regardless where it is plugged in, then it is the fan. If it is the fan, you can just by a replacement one or get a new cooler. It's up to you. 

 

The CPU cooler cannot operate properly without a fan. Yeah, it idles fine, as the heat output is enough that the cooler can passively cool it. Under load, however, the temperature will continue to rise until the CPU throttles severely in order to keep itself cool or eventually the computer will shut of due to overheating. 

After unpluging the GPU the CPU fan started spinning.

[Md z]

19 hours ago, EddE171 said:

Your motherboard is probably the issue. And it is safe but your performance will significantly drop if the temps get too high

After unpluging the GPU the CPU fan started spinning.