My intel iMac's fans gets louder then usual

Question

iMac Intel 21.5" EMC 2428 Mid 2011

Model A1311 / Mid 2011 / 2.5 & 2.7 GHz Core i5 or 2.8 GHz Core i7 Processor

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Ruslan @u378

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crwdns2931729:0crwdne2931729:0: Yan 21, 2019

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My intel iMac's fans gets louder then usual

got mid 2011 21” imac, i disassembled it all (without removing heatsink), cleaned both fans and motherboard and installed everything back into case. Fans acting as usual on start, but then starts rotating faster, after 1 or 2 minutes. and even more faster and louder if im watching movie. If i close the movie - fans wont get back to normal silent speed(

Any guess? Thanks

sensors

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You'll need to monitor what sensor is getting hot so you can address the problem.

Install TG Pro then post the main window so we can see the sensors (often times you need to grow the windows a bit so all the sensors are seen) Adding images to an existing question

crwdns2934271:0Yan 21, 2019crwdnd2934271:0 Dan crwdne2934271:0

Have you changed your hard drive?

crwdns2934271:0Yan 21, 2019crwdnd2934271:0 mayer crwdne2934271:0

yes i did, i put the new ssd drive, but i did the same thing 2-3 times before with 21" mac with success (yes i know about thermal sensor in 27" macs hdd).. And btw i put back an old HDD and... same thing: fans getting louder and louder...

crwdns2934271:0Yan 21, 2019crwdnd2934271:0 Ruslan crwdne2934271:0

Did you ever resolve this?

crwdns2934271:0Sun 29, 2025crwdnd2934271:0 Jon crwdne2934271:0

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crwdns2933315:02crwdne2933315:0

You'll need to monitor what sensor is getting hot so you can address the problem.

Install TG Pro then post the main window so we can see the sensors (often times you need to grow the windows a bit so all the sensors are seen) Adding images to an existing question — Dan
yes i did, i put the new ssd drive, but i did the same thing 2-3 times before with 21" mac with success (yes i know about thermal sensor in 27" macs hdd).. And btw i put back an old HDD and... same thing: fans getting louder and louder... — Ruslan

score 1 · Answer 1 · 2019-02-21T19:09:48-07:00

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Dan @danj

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Self employed contract worker

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crwdns2931729:0crwdne2931729:0: Yan 21, 2019

crwdns2933897:0crwdne2933897:0

If you haven’t installed the needed thermal sensor you’ll need to do that OWC In-line Digital Thermal Sensor for iMac 2011 Hard Drive Upgrade. Using fanControl software doesn’t really work that well and your system will not last as long.

Your system likely needs a bit of dusk cleaning after we see the TG Pro snapshot we can get into wants needed.

I don't see any issues with the thermal sensors. So SMC is encountering a different issue. I'm suspecting you damaged one of the ferrite beads (L5500 through L5531) near the sensor connectors on the logic board.

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just updated my question with the screenshot

crwdns2934271:0Yan 24, 2019crwdnd2934271:0 Ruslan crwdne2934271:0

ferrite beads are fine, mb is fine, did a PRAM reset twice…(

TG Pro is working fine, but! its wont decrease fan speed when CPU isnt very busy anymore

im sad(((

crwdns2934271:0Yan 26, 2019crwdnd2934271:0 Ruslan crwdne2934271:0

OK lets see if we can get a hint from diagnostics. Restart the system and press and hold the D key. Did an error pop? If it did what was the error code.

crwdns2934271:0Yan 26, 2019crwdnd2934271:0 Dan crwdne2934271:0

Aaaand no diagnostics window. at all. :D long pressing D does nothing. just looong time classic gray screen and then it boots normally

crwdns2934271:0Yan 28, 2019crwdnd2934271:0 Ruslan crwdne2934271:0

Do you have a USB keyboard? Give that a try.

crwdns2934271:0Yan 28, 2019crwdnd2934271:0 Dan crwdne2934271:0

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