crwdns2936637:0crwdne2936637:0 crwdns2853008:0crwdne2853008:0 crwdns2918746:0crwdne2918746:0

A2115 / 2019 / Processors from 3.0 GHz 6-core i5, up to 3.6 GHz 8-core i9. Released March 19, 2019.

crwdns2934591:020crwdne2934591:0 crwdns2934593:0crwdne2934593:0 | crwdns2947278:020crwdne2947278:0 crwdns2947270:0crwdne2947270:0

crwdns2933897:0crwdne2933897:0

Fan not spinning, SSD replaced

Long Story:

My girlfriends iMac has been going extremely slow so thought I would attempt to upgrade it since it had a fusion drive. I bought a new SSD (1TB OWC Aura Pro X2 PCIe) and 64 GB ram (OWC 2666Mhz). The install went well and before reattaching screen I thought we would test it out, booted up fine, and installed mac sequoia on the new SSD.

Was reasonably fast for first 5-6 minutes, but then started to get real slow. Clicking on anything on system settings would take 30-40 seconds before switching menus.

Shorter Story:

(Replaced SSD and Ram)


Upon pulling screen back with Mac still on, I noticed an extreme amount of heat coming out and the main fan in center was not spinning. Did some googling and downloaded macs fan control, put it on full blast, still nothing, shows 0 rpm in MFC.

I went ahead and ordered a new fan and pulled the existing fan out. With the existing fan I cut off the connector and put 12V between Pin 1 and 2 from the left and fan would jump, stop, then spin full blast so it seems like the fan itself was probably good.

Any ideas of what issue could be once I get the new fan in? Everything else I've read says the logic board itself, but if there are other ideas I'd love to hear them.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0
crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0

crwdns2933313:01crwdne2933313:0

crwdns2934221:0crwdne2934221:0
crwdns2931211:0crwdne2931211:0 crwdns2931215:0crwdne2931215:0 crwdns2934225:0crwdne2934225:0

crwdns2933897:0crwdne2933897:0

If you noted there are four wires with these fans looking at Step 24 in this guide iMac Intel 27" Retina 5K Display 2019 Fan Replacement

These fans use a tachometer to measure the fans RPM's so one just can't apply power to just any two pins (wires) and the polarity is also important. So one can't assume the fan is good just because you got a small movement more likely the bearing was frozen and applying power managed to break the seized bearing. I wouldn't trust it just the same and as you have a replacement on the way I would just put in the replacement.

As far as the system running slow without the fan SMC will lower the CPU's Clocking pushing the system into CPU Safe Mode to prevent the CPU from overheating.

Which drive did you replace? Was this a Fusion Drive system?

crwdns2934105:0crwdne2934105:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0
crwdns2889612:0crwdne2889612:0 0

crwdns2944067:04crwdne2944067:0:

This was indeed a fusion drive, 32gb ssd with 1 TB HDD. I left the HDD in place, and replaced the SSD with a 1TB SSD.

Also want to add I believe the fan was having problems before I replaced anything because the power cable between power supply board and logic board was semi melted to the board.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@shaneander92997 - I'm a bit confused how did you add the SATA SSD? The mounting should be where the HDD is.

Sadly, the power cable I'd part of the power supply so you may need to add some insulation on the damaged section and make sure the wires aren't crossed shorting out.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@danj

I replaced the blade SSD on back of logic board. I left the SATA HDD as is, sorry may not be using right terminology.

New fan should arrive on Sunday and I'll update on status of replacement.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@shaneander92997 - do you have access to a second Mac? You’ll need to wipe the HDD drive fully to remove the hidden partitions so you can reuse it. Setup a bootable OS installer to boot the system.

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

crwdns2934285:0crwdne2934285:0

crwdns2934229:0crwdne2934229:0

Shane Anderson crwdns2934231:0crwdne2934231:0
crwdns2936625:0crwdne2936625:0:

crwdns2936751:024crwdne2936751:0 26

crwdns2936753:07crwdne2936753:0 26

crwdns2936753:030crwdne2936753:0 26

crwdns2942667:0crwdne2942667:0 26