Fan Constantly On From Start Up

[tedmoo]

Hi there,
*
I know a lot of people have had this problem, but I can't seem to fix it!
*
My fan is on constantly, full RPM (very loud and annoying). It starts the second I wake up the computer or turn it on (cold); so it's not overheating.
*
There are no processes running that are 100% CPU time or anywhere close to 100%.
*
The clock seems to reset and need to be updated(not everytime I reset though). Also when waking from sleep it does the boot thingy (like hibernation) instead of waking up straight away.
*
It's a Macbook Pro (2010 A1278) 2.4ghz intel core 2 duo, upgraded to 8gb (ddr3) ram in December and a new 750gb (hybrid HD). Running 10.8.3
*
I've cleaned the fan and it blows nice cold air.*
*
I'm worried the logic board is dying and my mac will suddenly die also!
*
I've read that it might be the Thermal Sensors on the logic board, not sure how to tell? (Istat has 7 temp's listed, none currently above 35c but mac sounds like a jet plane)
*
Istat pro says exhaust fan 0rpm, Smcfancontrol doesn't work.
*
Tried reseting SMC and PRam. (multiple times). The hardware test does't work (pressing D on boot), pressing option-d on boot loads internet recovery(don't have original disks).

Sometimes (1/10+) I press sleep and wake the laptop up and the fan will be silent, and not come on at all no matter how hot mac gets.
*
I don't know what to do now!? I've seen logic board repairs for around £130 but can't afford that.

Any help will be much appreciated.
*
Thanks Very Much
*
Steve

 

[S.B.G]

Hi there,
*
I know a lot of people have had this problem, but I can't seem to fix it!
*
My fan is on constantly, full RPM (very loud and annoying). It starts the second I wake up the computer or turn it on (cold); so it's not overheating.
*
There are no processes running that are 100% CPU time or anywhere close to 100%.
*
The clock seems to reset and need to be updated(not everytime I reset though). Also when waking from sleep it does the boot thingy (like hibernation) instead of waking up straight away.
*
It's a Macbook Pro (2010 A1278) 2.4ghz intel core 2 duo, upgraded to 8gb (ddr3) ram in December and a new 750gb (hybrid HD). Running 10.8.3
*
I've cleaned the fan and it blows nice cold air.*
*
I'm worried the logic board is dying and my mac will suddenly die also!
*
I've read that it might be the Thermal Sensors on the logic board, not sure how to tell? (Istat has 7 temp's listed, none currently above 35c but mac sounds like a jet plane)
*
Istat pro says exhaust fan 0rpm, Smcfancontrol doesn't work.
*
Tried reseting SMC and PRam. (multiple times). The hardware test does't work (pressing D on boot), pressing option-d on boot loads internet recovery(don't have original disks).

Sometimes (1/10+) I press sleep and wake the laptop up and the fan will be silent, and not come on at all no matter how hot mac gets.
*
I don't know what to do now!? I've seen logic board repairs for around £130 but can't afford that.

Any help will be much appreciated.
*
Thanks Very Much
*
Steve

When you upgraded your HDD, did you reconnect (or could you) the HDD temperature sensor?

Try this and see if it works.

Controlling the fan speed in Mac models after an SSD upgrade.

 

[tedmoo]

Thanks for the super quick response.

I'm not sure tbh, but its been 3months working fine. Then suddenly two days ago mac started this problem - immediately noticed it sounding like a hairdryer.

Will check later after work, but don't know what the sensors look like?

 

[S.B.G]

Thanks for the super quick response.

I'm not sure tbh, but its been 3months working fine. Then suddenly two days ago mac started this problem - immediately noticed it sounding like a hairdryer.

Will check later after work, but don't know what the sensors look like?

It would be a small wire either attached by adhesive or plugged into the jumper block of the HDD

 

[tedmoo]

Cool i'll look later, no time to open up now. But I appreciate your help!

Tried the Automater thingy, didn't work, but probably because not using it correctly.

Also saw somewhere else to try in Terminal, but didn't do anything (fan still going strong), but didn't return an error code like what you put in Automater.

 

[tedmoo]

Had a look for the sensor, couldn't see anything. Not sure what to look for really.

Although in System Information it shows Temperature Monitor. I don't know if this is normal or not, can't remember if it was always there?

 

[tedmoo]

I eventually found my Install disks, wooo!!

AHT (Apple Hardware Test) detected error:

4MOT/4/40000002: Exhaust -0

From searcing arround apparently the MOT stands for Motor and exhaust is the fan?

Just need a Torx screwdriver now too see if any loose wires. Hopefully a new fan for £15 will sort my problem.

Thanks for all your suggestions and help.

Anyone know if the Apple Service Diagnostics will provide further information?

 

[white95supra]

I am having the same problem on my MBP A1278 and have not been able to figure out the solution. Can you tell me if replacing the fan fixed the problem?

 

[Big-TDI-Guy]

The fan can be functioning - but if the tach / feedback is not - those fans will usually default to 100%.

So if your temps are all in range using iStat or SMC Fan Control - and your fan is showing 0RPM or error (while you can hear it running) - that's it. If you get 0 RPM - and the fan isn't spinning, it's either locked / jammed - or has failed.

Replacing the fan should fix it - providing the issue is the tach generator - however there is a small chance your logic board is simply failing to read the tach signal from the fan.

Considering the cost and ease of replacement - you're much better off trying the fan swap.

 

[S.B.G]

Cool i'll look later, no time to open up now. But I appreciate your help!

Tried the Automater thingy, didn't work, but probably because not using it correctly.

Also saw somewhere else to try in Terminal, but didn't do anything (fan still going strong), but didn't return an error code like what you put in Automater.

Did you ever get this resolved yet?

 

[white95supra]

The fan can be functioning - but if the tach / feedback is not - those fans will usually default to 100%.

So if your temps are all in range using iStat or SMC Fan Control - and your fan is showing 0RPM or error (while you can hear it running) - that's it. If you get 0 RPM - and the fan isn't spinning, it's either locked / jammed - or has failed.

Replacing the fan should fix it - providing the issue is the tach generator - however there is a small chance your logic board is simply failing to read the tach signal from the fan.

Considering the cost and ease of replacement - you're much better off trying the fan swap.

Thanks, I will buy a new fan and give it a shot.

 

[tedmoo]

Hi there,

Just quick note that replacing the fan didn't work for me. My mac is still screwed and won't turn on at the moment (stuck on spinning apple logo)

 

[S.B.G]

Hi there,

Just quick note that replacing the fan didn't work for me. My mac is still screwed and won't turn on at the moment (stuck on spinning apple logo)

Oh that's not good. Maybe its time to take it in and have the Apple Store repair it.

 

[vpro]

I've had that.

My 2006 17"MBP started to do that about 2 years after I bought it. The fan would just roar upon initial log in and stay roaring till shut down. They did everything under the sun for 3 years after that, nothing improved, 5 logic boards later and all sorts of re-wiring etc...

Finally I got really angry because it always sounded like there was a jet engine in my apartment and have been using my mbp fans disconnected! As soon as it is hot, I shut down or place ice packs underneath with a waterproof sheet or just plastic bag, works WONDERS... (*There is never any pooling water around the device and desk anywhere, only inside the sealed packs).

Good luck to you!!