21.5' iMac fan speed is to fast

Hello Everyone,

Jerry reporting in again.

Well, as everyone has noted, the HD replacement on my iMac I reported on last
time has indeed solved the fan problem. I ran the computer without
sleeping for about ten days and it was gone.
My new HD is ST3500418ASQ.

As I said, the Apple folks at the Apple store in Salem
seemed to be aware of the problem but no one but
me has come in for the HD replacement.

They did move everything from my old disc to the new one.
That will take a while depending on how much data you
have on your HD.

So, looks like we have a permanent solution for those
who want it and and simple work around as well.

Thanks to all for your effort.

Jerry

Hello All,

My first post on the Apple forum. I to am having this issue with my new iMac 21.5in base model. Purchased a few days ago with the 500GB drive then returned it due to the jet fan noise and now having the exact same problem. Everyone seems to have the Hitachi HDD, but the drive I have, that came stock, is a Seagate.

When researching upgrades for this iMac, I found that I should purchase a Seagate to match the unit since the new macs were not interchangeable, as OWC says.

(At the bottom of the page and you can see where OWC briefly explain how to determine your HDD)
http://eshop.macsales.com/shop/memory/iMac/2010/DDR321.527

I decided to go with the Seagate 1.5TB HDD as an upgrade. After installing, I am still getting really high fan noise. Seems that this wasn't the answer.

CPU Fan is running at 1199rpm and stays there pretty consistently.
HDD is Running at 5661
And overall temp is about 32 degress F

Only application open right now is Google Chrome. But this noise is annoying. I've updated to the latest software, so I am not sure what else to try. Should I give Seagate a call to see if it is there drive? The fan hasn't shut off since 3pm today, its now 12:30am and still blowing. Again, only app open has been chrome.

Hello JPizzle

You may NOT have the same problem as we have.

1. Ours only occurred weekly.

2. Ours can be stopped by sleeping and then waking the iMac.

3. Ours has only occurred with Hitachi HDs and has been fixed by HD
replacement, typically to a Seagate.

4. Our Macs were bought early on, I think before March 2010.

So, I am not sure what to tell you.

Jerry Fleischman

It make me crazy, I need to turn it to sleep mode every 15mins for stop the HDD fan noise(5200 rpm...), Apple support team, please fix it asap.

Hello folks... its been a while... here is an update to this and hopefully some good news to you all.

This issue is (as I mentioned previously) a hard drive firmware problem. Apple has a firmware update that is available to resolve the problem, however it will NOT be released to the public due to the possibility of data loss or bricking the hard drive.

If you want this problem repaired, the machine needs to be worked on by an Apple Authorized Service Provider, or by an Apple Store. PLEASE MAKE SURE YOUR DATA IS BACKED UP. They will either replace your hard drive or run the firmware update (depending on if they have the update available to them).

45 of the 46 iMacs I have that had the problem were fixed today by my Apple Engineer contact (one couldn't be fixed due to a recent power supply failure). The firmware update went smoothly and I'll know in about 7-8 days if it really worked. Stay tuned...

I'm sure they have this resolved, however for the average user, this means you will need to take in your machine or call AppleCare to coordinate a repair with a local Apple Service Provider.

Hope this information finally confirms/addresses this issue for you all.

Is there any sort of case or issue number that we're able to reference?

Ultimately final info:

This affects the Late 2009 21.5" *AND 27"* models with the following hard drives...

500 GB, model HDT721050SLA360 is affected.
and 1 TB, model HDE721010SLA330 is affected.
Revision must be ST0KA36E.

If you have a machine with the fan issue, check the hard drive information in the System Profiler under Serial ATA. Click on the hard drive option for the model and revision code.

If the machine is affected, the hard drive should be replaced per Apple.

When calling this in or taking the machine to an Apple Store or Apple Authorized Service Provider, reference KB article "TS3350".

I seem to be having the same issue only with a 27" i7. According to iStat fan speeds are

Optical Drive ~3500rpm
Hard drive ~1100rpm
CPU ~3900rpm

Followed the SMC reset steps but still getting the fans making lots of noise 😟

Checked the Hard drive details, but they're completely different, also the fan speed for that seems fine, just the optical drive (which is strange since I don't think that's ever been used) and the cpu.

That seems to be a completely different problem. On this particular issue, the hard drive fan itself runs up to 5K+ for no reason, with all other fans in normal range.

Hi Jason

I've been reading (some of) this thread with interest. I have been experiencing the fan issue on my refurbed 21.5" iMac purchased in August this year. I checked my hard drive and it is exactly the Hitachi model and revision you specify.

I cannot locate the knowledgebase article you reference - is that ID "TS3350" correct? Can you post a link to the article?

TIA...M

Jason, you're a star 🙂

Just called Apple Care and am getting my drive replaced asap. Actually gonna try and get a 2T drive rather than the current 1T I have.

Great stuff, and perfect info. Everyone else, start calling Apple if you've being having this issue !!!

Do you have the link to the KB article? I can't seem to locate it anywhere.

Hey everybody! First off I would like t add myself to the list of people affected by this problem and, secondly, I would like to thank all those in this thread who helped to pin down the causes of the annoying fan problems in late 2009 iMacs. I don't exactly know who you are because the thread is incredibly long, but still many thanks to all!

I will be taking my iMac in for repair with all this info in hand to request an HDD replacement, hope everything goes smoothly!

Regards,


- jmpp

I'd like to also say that I'm also having this same exact problem. KB TS3350 is the correct KB # for this problem.
I had to take my 27in Imac in for a screen problem (grayish lines in the display), told the first guy about this discussion, and my problems and he documented my account, refused to look at the KB. I returned a week later after the replacement part finally came in, talked to a second guy, who refused to take the KB #, but said 'they would look into it'. I went last night to pick up the Imac after repairs were done, well.. the harddrive passed all there tests, no replacement.
After 'shoving' a post-it note with the KB TS3350 on it, and describing the 35-page discussion (again), and including that my brother's IMac doesn't have this issue (his has the WDC hdd in it). He finally looked up the KB article, verified the hard drive model number, and I am now getting a replacement hard drive... So if anyone else wants to go in due to this problem, make sure you take 'KB TS3350' with you and force it upon them if needed.

Hello guys, I think I solved the problem of fan noise after replacing the original 500 gb hd with a 2TB in my case a model WD wd20ears.

The problem we found is that everyone immediately after replacing the disk after 10 minutes of hd the fan is not feeling up to the presence of the temperature sensor.

To make the measurements on the temperature and fan speed hd I use istat menus 3.

As you can see without connecting the temperature sensor istat menu is able to measure the temperature of the disk via the SATA interface, but the operating system can not measure the temperature of the HD, then go up to the fans after 10 minutes , making it almost unusable on your Mac.

Follow these steps:

1) install the new hd with the circuits up.

2) Connect the wires from the temperature sensor to the jumper as I will describe below! (Those who normally use to set master or slave disk)

XXOX

XXOX

the wires are connected where there are zeros, where there are x jumpers are free.

The black wire of the sensor goes to zero than the gray one less zero.

If it does not reverse the polarity, nothing happens will not burn out the device, the important and you do not use other jumpers do not know what could happen.

3) if you have properly connected the wires to the jumpers when you restart your imac istat menu to see inside the sensor 's hd does not measure the correct temperature, but the fan speed after 10 minutes but is still not crazy as internal manual to 1100 rpm.

4) you will see that as before there will be a subheading in istat your hd with the correct temperature.

Finally,

this means that the jumpers are used as a switch to alarm the motherboard in case of exceeding critical temperature and starts the fan until the contact opens again down in temperature.

Now you can use your iMac with a nice hd 2TB without becoming deaf.

Sorry for the translation

Stefano