Hey all, thanks in advance for any insight....
2017 iMac 3.8Ghz/40GB/2TB Fusion/Radeon 580 8GB EMC 3070
Decided to upgrade my iMac blade, HDD and CPU. Read up rather extensively on rsx0’s post here and others to determine the best course. I have previous experience upgrading HDDs, adding SSDs and upgrading the CPU in my previous 27” 2010 iMac.
I gathered the following:
I7-7700k CPU, previously owned, delidded to add liquid metal.
1TB Feather Turbo blade SSD, according to their listings, it is compatible and loaded with High Sierra
10TB Seagate Barracuda HDD (lots of files for photography hobby...OWC SATA adapter with temp sensor bought for this)
Took on the project and all went well. Installed everything as the write ups and videos demonstrated. Blade and HDD were no problem. Had significant difficulty with the retaining spring on the CPU, but managed to get it mounted....or so I thought.
Reassembled and power on. Nothing happens. Diagnostic LEDs have LED 1 illuminated and LED 2 would blink as long as power button was depressed but nothing further and would not stay illuminated.
Note: I did not clone anything to the HDD or Blade...I have a backup of my files and the Feather supposedly came loaded with High Sierra, so my intent was to boot into that, upgrade to Mojave, rebuild the fusion drive and then migrate my files.
Tore everything down to see what I might have done wrong, but all connections were fine. Got to the CPU and disassembled it. When I first installed the i7, I fell into the same trap and it had shifted in the heat sink. The CPU was slightly bent in the corner and one of the pins on the socket had been bent. In the process of removing the CPU it decided to delid itself as the cryonaut holding it to the heat sink was stronger than the RTV holding the IHS to the CPU.
Carefully straightened the CPU board and meticulously bent the socket pin as close to alignment as possible. That was fun. Cleaned and reapplied conductonaut and relidded the CPU with new RTV.
Reinstalled the CPU and heat sink using cryonaut. Rebuilt CPU and power on. Nothing on screen. No illumination. Check diagnostic LEDs.
LED 1 illuminates, then LED 2 as the HDD spools. Then, the HDD spools down and LED 2 goes out. HDD spins up again and LED 2 comes back on and stays lit, but following that nothing else happens. Fan is spinning.
Trying to boot into anything at this point, safe mode, diagnostic mode, rescue...can’t get it to boot off of a Mojave install USB. Keyboard does not connect (caps lock light wont illuminate, full battery charge) whether wireless or wired to USB or Thunderbolt, so I am guessing it isn’t even getting commands from the keyboard to boot into other modes.
Removed HDD and installed Mojave directly onto that from another iMac, no help.
When powering on, there is no activity on the USB drive light (the one with the Mojave installer)
So...I think something is dead here. Where do I go next? Do I reinstall the i5? Do I reinstall the OEM SSD? I suspect the SSD is not the issue since I cannot get it to boot from the OS installed on the HDD even. Could I have wrecked something else (anything is possible) that is a better starting point based on the behaviour of the diagnostic LEDs?
Any help is very much appreciated.
2017 iMac 3.8Ghz/40GB/2TB Fusion/Radeon 580 8GB EMC 3070
Decided to upgrade my iMac blade, HDD and CPU. Read up rather extensively on rsx0’s post here and others to determine the best course. I have previous experience upgrading HDDs, adding SSDs and upgrading the CPU in my previous 27” 2010 iMac.
I gathered the following:
I7-7700k CPU, previously owned, delidded to add liquid metal.
1TB Feather Turbo blade SSD, according to their listings, it is compatible and loaded with High Sierra
10TB Seagate Barracuda HDD (lots of files for photography hobby...OWC SATA adapter with temp sensor bought for this)
Took on the project and all went well. Installed everything as the write ups and videos demonstrated. Blade and HDD were no problem. Had significant difficulty with the retaining spring on the CPU, but managed to get it mounted....or so I thought.
Reassembled and power on. Nothing happens. Diagnostic LEDs have LED 1 illuminated and LED 2 would blink as long as power button was depressed but nothing further and would not stay illuminated.
Note: I did not clone anything to the HDD or Blade...I have a backup of my files and the Feather supposedly came loaded with High Sierra, so my intent was to boot into that, upgrade to Mojave, rebuild the fusion drive and then migrate my files.
Tore everything down to see what I might have done wrong, but all connections were fine. Got to the CPU and disassembled it. When I first installed the i7, I fell into the same trap and it had shifted in the heat sink. The CPU was slightly bent in the corner and one of the pins on the socket had been bent. In the process of removing the CPU it decided to delid itself as the cryonaut holding it to the heat sink was stronger than the RTV holding the IHS to the CPU.
Carefully straightened the CPU board and meticulously bent the socket pin as close to alignment as possible. That was fun. Cleaned and reapplied conductonaut and relidded the CPU with new RTV.
Reinstalled the CPU and heat sink using cryonaut. Rebuilt CPU and power on. Nothing on screen. No illumination. Check diagnostic LEDs.
LED 1 illuminates, then LED 2 as the HDD spools. Then, the HDD spools down and LED 2 goes out. HDD spins up again and LED 2 comes back on and stays lit, but following that nothing else happens. Fan is spinning.
Trying to boot into anything at this point, safe mode, diagnostic mode, rescue...can’t get it to boot off of a Mojave install USB. Keyboard does not connect (caps lock light wont illuminate, full battery charge) whether wireless or wired to USB or Thunderbolt, so I am guessing it isn’t even getting commands from the keyboard to boot into other modes.
Removed HDD and installed Mojave directly onto that from another iMac, no help.
When powering on, there is no activity on the USB drive light (the one with the Mojave installer)
So...I think something is dead here. Where do I go next? Do I reinstall the i5? Do I reinstall the OEM SSD? I suspect the SSD is not the issue since I cannot get it to boot from the OS installed on the HDD even. Could I have wrecked something else (anything is possible) that is a better starting point based on the behaviour of the diagnostic LEDs?
Any help is very much appreciated.
