CPU Fan Speed not going above 2500rpm [Predator PT 315-51]

AlexJMercer
AlexJMercer Member Posts: 5

Tinkerer

Hello, my Predator laptop is just over 13 months old, and recently,(since about a month) it has been getting a bit too hot during normal use, i.e., a few chrome tabs, one Adobe PDF and Microsoft Teams. The CPU reaches around 80 degrees at times like this. This wasn't the case before, it used to be around 70 degrees. I DO have my GPU disabled because I don't need it during normal use. It was today that I discovered that the CPU fan isn't going above 2500 rpm at all. Of course I know it goes to around 6100 rpm max, and I think that's why I'm having cooling issues. Also, the fan is making whining noises, it sounds like it's hitting something. I did open it up to clean the dust inside, and that was in September, i.e, 2 months ago. It was fine after the clean-up for about a month. The noise was there even before I cleaned it. I'm concerned why the fan isn't able to run at full speed, is it dust ? I didn't take out the fan completely, just used canned air for that. Any solutions ? The noise is really annoying.


Best Answer

  • AnhEZ28
    AnhEZ28 ACE, Member Posts: 4,518 Pathfinder
    Answer ✓
    @AlexJMercer so your current problem is about the low RPMs of the CPU fan which leads to high temps right? The noise might be from dust sticking on to the fan bearing. Try to clean the inner of the fan like in this video https://www.youtube.com/watch?v=1JVtNY51-Uc
    Please remember to include @AnhEZ28 when you want to reply back to my comment so that I can check your response.
    Thank you and have a nice day!

Answers

  • AnhEZ28
    AnhEZ28 ACE, Member Posts: 4,518 Pathfinder
    @AlexJMercer it could be dust in the fan bearing. You can try taking the fan blade out and clean it, or you can add a bit of oil.
    Please remember to include @AnhEZ28 when you want to reply back to my comment so that I can check your response.
    Thank you and have a nice day!
  • AlexJMercer
    AlexJMercer Member Posts: 5

    Tinkerer

    AnhEZ28 said:
    @AlexJMercer it could be dust in the fan bearing. You can try taking the fan blade out and clean it, or you can add a bit of oil.
    How would you recommend cleaning the fan after completely taking it out ? Would just soap and water be okay ?
  • AnhEZ28
    AnhEZ28 ACE, Member Posts: 4,518 Pathfinder
    edited November 2021
    @AlexJMercer nope, that would destroy the fan. You can use something like a old toothbrush or small paint brush for cleaning the fan and motor.
    Please remember to include @AnhEZ28 when you want to reply back to my comment so that I can check your response.
    Thank you and have a nice day!
  • AlexJMercer
    AlexJMercer Member Posts: 5

    Tinkerer

    AnhEZ28 said:
    @AlexJMercer nope, that would destroy the fan. You can use something like a old toothbrush or small paint brush for cleaning the fan and motor.
    Wait, I meant cleaning it after completely disassembling the cooling assembly and taking out the fans. I have already cleaned them using an old paintbrush, but I can see dirt sticking to the sides of the fan fins, and that's very very hard to get rid off. Cooling did get better after a paintbrush session, however after 2 months, the temps are back up again. 
  • AnhEZ28
    AnhEZ28 ACE, Member Posts: 4,518 Pathfinder
    @AlexJMercer for reducing the temps, you can take out the heatsink, clean the old thermal paste, and put a new thermal paste.
    Please remember to include @AnhEZ28 when you want to reply back to my comment so that I can check your response.
    Thank you and have a nice day!
  • AlexJMercer
    AlexJMercer Member Posts: 5

    Tinkerer

    AnhEZ28 said:
    @AlexJMercer for reducing the temps, you can take out the heatsink, clean the old thermal paste, and put a new thermal paste.
    That leaves the whirring noise...any ideas what could be causing that ? The noise comes only from the CPU fan, not the GPU one. Coincidentally, the CPU fan is the one which can't spin at max rpm as of now.
  • AnhEZ28
    AnhEZ28 ACE, Member Posts: 4,518 Pathfinder
    Answer ✓
    @AlexJMercer so your current problem is about the low RPMs of the CPU fan which leads to high temps right? The noise might be from dust sticking on to the fan bearing. Try to clean the inner of the fan like in this video https://www.youtube.com/watch?v=1JVtNY51-Uc
    Please remember to include @AnhEZ28 when you want to reply back to my comment so that I can check your response.
    Thank you and have a nice day!
  • AlexJMercer
    AlexJMercer Member Posts: 5

    Tinkerer

    AnhEZ28 said:
    @AlexJMercer so your current problem is about the low RPMs of the CPU fan which leads to high temps right? The noise might be from dust sticking on to the fan bearing. Try to clean the inner of the fan like in this video https://www.youtube.com/watch?v=1JVtNY51-Uc
    You're right. I just opened up my laptop to see what the problem possibly might be. Turns out, the CPU fan is kinda stuck. Yes, there's a lot of dust inside, not outside because I cleaned that. I didn't open them up any further today because that'd require me to dis-assemble the entire cooling system, and I don't have any thermal paste as of now. However, the problem is clear to me now. The dust has built up inside the rotor itself, and that's the reason the fan is limited to 2500rpm. This is not the case with the GPU fan and that's why it's able to work normally without whirring noises. Thanks for your help !