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Fans kick in when HDMI port is used

When I connect a TV to HDMI port, then fans start to kick in seriosly without noticeable CPU load increase. I've also tried to use Thunderbolt-to-HDMI adapter instead of using HDMI port directly and got same effect.

I have my external monitor connected using Thunderbolt-DVI adapter and everything is fine and MacBook is super quiet.

Fans don't directly kick in based on CPU load, but rather on MacBook casing temperature. I guess something in HDMI singnal generating code is heating up something inside MacBook and fans kick in to compensate for that.

Not sure if it's normal or not.

They are probably compensating for the increased load on the GPU.

You can try a SMC reset:

https://support.apple.com/kb/HT3964

Follow directions for a battery you should not remove yourself

Also make sure the MBP is on a hard flat surface to provide adaquate ventilation.

They are probably compensating for the increased load on the GPU.

I wonder if it's a standard behavior, because I haven't seen this described anywhere in docs. I guess if I connect 3 monitors as once I will get even higher fan noise, which is dissapointing.

 

You can try a SMC reset:

 

https://support.apple.com/kb/HT3964

Follow directions for a battery you should not remove yourself

 

And this magic sleep/reset/shutdown combination will do SMC reset for sure? Doing that SMC reset won't erase anything on my mac or reset any settings I've set in "System Settings?

aik099 wrote:

 

And this magic sleep/reset/shutdown combination will do SMC reset for sure? Doing that SMC reset won't erase anything on my mac or reset any settings I've set in "System Settings?

Will not erase anything and do no harm.  May do some good.

Ciao.

Thanks, I'll try that later today and post the results. Rebooting is not what I'm used to do so ofter with Mac (in contrast to Windows).

Doing SMC reset didn't do anything. Right fan speed was increasing towards 3000rpm, where it's usually 1999rpm.

Execute an Apple Hardware Test.  That may offer some clues:

https://support.apple.com/kb/ht1509

Ciao.

All ports works, then what AHT can tell me more about that? It can't really write me "your fan kicks in because ...", can't it?

I'm not suggesting that the AHT WILL find a problem, but it may.  It might develop that there is a bad voltage sensor that may be relevant to your issue.  It also may tell us nothing.  It is your decision to run it or not. 

Ciao.

AHT showed this error:  4HDD/11/40000000: SATA(0,0)

For a Mac, that only 1 year old I think it's very bad. And I surely know, that I don't have any SSD problems.

The error that the AHT developed indicates a connection problem with the SSD.  Make an appointment at an Apple store genius bar and have them perform their more extensive tests.  Tell them the error code that you developed from the AHT as well as the other symptoms the the MBP has shown.

Ciao.

Message was edited by: OGELTHORPE

Anyone looking for a way to avoid the loud fan noise when connected to HDMI should try changing the display settings through "about this mac" then select "display" then "display preferences" then optimize the display to suit tv.  My tv is Samsung so i select Samsung from the list. Note it has to be connected to another screen to see another option in list. Also if you want to see if the fan is running at the correct speeds you can download "Macs fan control".

最後更新：2017-09-29 04:56:16

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