Chosen Solution

I can’t boot into MacOS, won’t go past Apple with the loading wheel. Recovery mode works for a while and crashes, graphics are just a bit slow and glitchy at times. I think the HDD is corrupted as verbose startup says The Volume Macintosh HDD could not be verified properly. I can sometimes boot into ubuntu if it does not go to a black/gray screen. If I boot into ubuntu and try to access my HDD it crashes, if not it eventually crashes anyway. I get BSODs both blue and black. This Mac’s GPU was repaired (reballed I think) a few years ago after it stopped working. Is the GPU dead or the HDD? I can provide pictures of whats going on as well. Tried PRAM, SMC resets already

AHT Results: https://imgur.com/a/y7ehnto Update (07/15/2019) Managed to get it on internet recovery

http://imgur.com/a/LnptCzM However no drive shows up, I’ll try to reconnect the cables, also whats up with the fan, its still spinning like crazy I think I figured it out from here forgot to transfer the hard drive emi foam I forgot to replace that EMI foam and I dont have it, is there another way to seat it temporarily using like tissue paper or something?

  • ran AHT and got this error, looks like ODD fan/sensor?

http://imgur.com/a/eksYvFj

Your error implies your HDD fan has failed! But! Your system doesn’t have a HDD fan only a CPU fan as you can see in this image from the iFixit teardown of the 2013 27” iMac:

So you either have a a major failure within your logic board SMC service or you have an older iMac maybe a 2011 or 2010?? Here’s a good write up on AHT Finding Hardware Faults: Exploring AHT & Apple Diagnostics jump down to Step 5. Update (07/11/2019) OK, I corrected your system info so its now correct. Here’s the HD fan unit you’ll need iMac Intel 27" (Late 2009-Mid 2011) Hard Drive Fan We don’t have a guide to get you the full way but we do have this guide Installing iMac Intel 27" EMC 2429 Dual Drive Kit (HDD or SSD) That will get you mostly there. Follow the guide to Step 33. From there you’ll need to finish removing the logic board disconnecting the last few cables. Once out you can gain access to the fan just behind it. I’m sure your GPU is also in trouble as well here. I would first see if cleaning off the old thermal paste and thermal pads and replacing both as needed, as well as clean out the dust build up within the system as a whole using a small soft paint brush and a can of can’ed air. After testing things with the fixed fan and refreshed thermal paste and pads see if the GPU is still encountering issues. You may need to replace it or reflow the GPU chip (very last option here) Update (07/16/2019) Here’s the logic board connections. Make sure Cable ‘‘‘C’’’ is firmly in place