HDD Temperature sensor gone in 2011 iMac?
It looks like the temperature sensor in the iMac for the hard drive if now gone in the teardown - can iFixit confirm?
If it has gone, this is great, as now I can add and remove a hard drive without Apple's specifications for a temperature sensor built in, like in 2009 and 2010 iMacs.
I'm copying a post comment in Appleinsider:
The OWC report is quite inaccurate and I wish they did some more testing or at least read the forums before creating mass panic.
The SATA data connectors are very standard and so is the SATA power cable feeding the hard drive. The only difference is that they used 7 wires instead of 5, probably some extra grounds.
I installed a Vertex3 SSD and used a plain 4 wire Y-splitter sata power cable which effectively discards the 3.3V from the apple's wiring and only feeds 5V and 12V to the original drive. Guess what, fan speed is as quiet as it can get and the Apple Hardware Test passes successfully.
I went further and moved the internal HDD from SATA0 to SATA1 port to better accommodate the SATA connector for the SSD and this didn't create any adverse effects.
Another member of the forum swapped the 1TB WD Black with a 2TB WD Black and again, no adverse effect, Hardware Test completed successfully.
With the SSD in place now, the only thing I can hear is my breath reflected by the glass screen
I am confident that the temperature sensor is one different to the S.M.A.R.T sensor fitted in all drives.
When you replace the HDD with a non-standard HDD (ie. not one that Apple have baptised and granted permission to live inside their oh so superior machine *NOT*), the iMac doesn't use the S.M.A.R.T data, and as such reports that there IS no sensor, or atleast that it's broken, so it kicks up the fans just in case the HDD has caught fire or has been blasted into the centre of the sun... Y'know... Just in case.
The solution to this is to effectively short the connector out. This allows for a current to flow and for the iMac to be of the impression that the temperature sensor is working and at optimum temperature.
Another POTENTIAL solution that I've yet to try is to buy a temperature sensor belonging to the OPTICAL drive. It shares the same connectors as the previous HDD sensor, and it performs the same task, so I can't see it failing. However, these are difficult to source and can be a little costly, so if I take that route, I'll update...
There's also a piece of software called HDD Fan Control or similar. I wouldn't bother though - It didn't help me very much.
Here is my update - Worked a treat.
So don't panic! You can choose any HDD you like - Use the old-fashioned method of sticking a temperature sensor to it from an old optical drive. Works brilliantly.