Question First time starting pc fans go loud and then slow and repeat

[Tomtommi12]

So I built my first pc and everything went well the pc turns on and the fans do normal but when I started my pc for the first time the fans started increasing in rpm and slowing down again and then increase in rpm thus causing some weird fan sounds. Is this normal on the first startup?

 

[william p]

Yes, and it may happen when power is completely removed from the system. It's just doing a more complete POST routine. Some fans have a delay that makes them speed up slowly for the test, then back down to what'srequired. The MB send a 100% speed signal, and then learns what RPM that represents which varies fron 1 fan to another. A fan without the 10s delay may speed up at every start.

 

[gleamrey]

So I built my first pc and everything went well the pc turns on and the fans do normal but when I started my pc for the first time the fans started increasing in rpm and slowing down again and then increase in rpm thus causing some weird fan sounds. Is this normal on the first startup?

Same problem , and my screen is going black .. it's been 2 week still didn't solved the problem , they said Try to Change PSU

 

[Ferimer]

Take a picture of what it looks like inside your case. You could be experiencing very high spikes of temperature which causes the fans to jump up really high. Check your temps download CPUid HW monitor and check your temps to ensure things are good.