iMac 27" (2009) dies at 60% of USB boot

[Bradamante]

Hi there,

so I have an old iMac here (late 2009, 27", 4GB RAM, EMC 2374). I am now trying to do a clean install of the OS by booting from a USB stick. I have both a 10.13.4 stick that I just created and an older 10.11.x stick that I used successfully in the past.

Problem is that when I hold ALT during boot I can select the USB stick, but the booting process from the USB stick always dies at around 60% (or maybe 70%, but always at the same point). I can also see the USB stick stop blinking at that point, so that means the iMac does not copy data anymore. I never even get to the OS install screen, it already dies during boot. I tried holding V for verbose mode during boot, but that doesn't seem to work.

I tried different USB ports. I tried swapping the 4 GB RAM for 8 GB, no change. Anything else I can do? What is going on here?

 

[Superspeed500]

I tried different USB ports. I tried swapping the 4 GB RAM for 8 GB, no change. Anything else I can do? What is going on here?

Have you tried to:

• Check the filesystem on the stick for errors (you can use Disk Utility or similar software).
• Run AHT on your Mac to check for defects.
• Reset NVRAM.
• Reset SMC.

Do you have Internet recovery on your Mac and if so do that work? Do the installation DVD (or similar) that came with your Mac work?

 

[elf69]

had same issue with 2007 imac.

ended up installing 10.7 from optical then putting my time machine backup on after the HDD failed and i swapped it for an SSD.

the older imacs seem fussy about usb sticks.
of my 10 sticks only 2 it will boot from, the rest hang like OP on 60-70% loading.

 

[Bradamante]

Hm would it be possible to boot those 2009 27" iMacs from a SD card, using the internal reader?

 

[Fishrrman]

My guess is that if it won't boot via USB (with the copy of the OS that you're using), putting the same copy of the OS onto an SD card isn't going to make any difference. The SD card slot is "on the USB bus", anyway.

 

[Bradamante]

Yeah I tried that now and again it dies at around 70%. With the card reader using USB internally that makes sense indeed.
So what is left to try? I don't have the original install DVDs. Installing an older OS than High Sierra is kinda pointless. I would only do that to prove that High Sierra specifically is the culprit.

Next up I want to try FireWire target disc mode, but that would require a notebook with FireWire that can boot High Sierra. So I guess I will have to borrow a MB or MBP from the 2010-2012 range somewhere ...

Can you create a bootable High Sierra DVD somehow? When I try to burn High Sierra's InstallESD.dmg to a DVD-DL with Toast, it says DVD doesn't have enough space (8.7 GB vs. 7.9 GB or something).

 

[jerwin]

https://forums.macrumors.com/threads/how-to-make-a-bootable-dvd-of-high-sierra-os-x.2072785/
https://forums.macrumors.com/threads/convert-the-high-sierra-installer-app-to-an-iso-update-success.2070676/
never tried it, though.

 

[Fishrrman]

OP wrote:
" Installing an older OS than High Sierra is kinda pointless."

No, it's not pointless.

I suggest you create a Low Sierra USB flashdrive installer and try that.
MAKE SURE you ERASE the internal drive first to Mac OS extended with journaling enabled.

I think there's a good chance that if you do this, the results may improve.

 

[Bradamante]

Yes it is pointless. My intent is to sell the iMac, not to keep it. Problem is that by my experience people don't buy used hardware unless you can prove that the current system runs on it.

Besides, I have already tried a different USB stick with an El Capitan installer and that doesn't boot either.

I have now tried putting the iMac into FireWire target disc mode and connecting it to a 2010 MBP. Interestingly the iMac's internal hard drive does not appear. To be honest I don't even remember if I formatted the new hard drive when I put it in or not.

Next up I will try creating a bootable DVD, either Lion, El Capitan or High Sierra.

EDIT: A bootable Lion DVD boots fine, but Disk Utility does not show any internal hard disc. I used a SSD to HDD casing/converter, hoping to solve the fan noise problem with a software tool later. I can't imagine something went wrong during install. But I guess I have to take apart the iMac one more time. Problem is the friggin VSync cable won't survive another reassembly.

 

[Bradamante]

I tried a few more things. I took a 2010 MBP with a working High Sierra install. Put it into FireWire target disc mode. Connect it to the iMac with a FW cable. Boot the iMac and chose the external FW volume. That works fine. It boots into HS, the data from the notebook is there, but with the hardware from the iMac. Installed MacsFanControl. The sensors and fans of the iMac are all accounted for. As expected, the HD sensor is missing, and the HD fan slowly ramps up.

Next I took the iMac apart again and tested the SSD inside the SSD-to-HDD converter by putting it inside an external enclosure for 3.5" hard drives. It was not formatted. Didn't know you have to do that. Formatted as HFS+ with Disk Utility. Installed High Sierra on it, converting it to APFS in the process. Put the disc back into the iMac.

Now the iMac is stuck in a booting loop, where the iMac restarts once it has reached around 60% of the boot process. What the heck?! Tried resetting the NVRAM, no change.

EDIT: Err, I now tried booting the iMac from it's internal hard drive while the MBP is connected in FW target disc mode. Now the iMac boots through into the desktop just fine. For the first time. But, as soon as I eject the MBP FireWire volume, the iMac shuts down and reboots, getting stuck again at 60% and then rebooting etc.

 

[jerwin]

Can you retrieve the relevant system.log?

 

[oldhifi]

EL captain works great on my 2009 IMac

 

[Bradamante]

Can you retrieve the relevant system.log?

I will try that tomorrow, booting the iMac into FW target disc mode and connecting it to a 2009 MBP (I just delivered the 2010 MBP I had before to a client).

I also tried booting with verbose mode. The last thing I see is the "gioscreenlockstate 3" line, which I only know from hackintoshes. Google doesn't produce useful results for standard Apple hardware, unfortunately. My current theory is that it's either graphics card or PSU related. It's possible that at 70% of the loading bar the graphics card is coming in and that taxes the PSU too hard, so it reboots. That doesn't explain why the iMac boots through when booting from a MBP that is in FW target disc mode or when said MBP is just connected, though. Another theory would be that one of the RAM slots is faulty.

Btw when I hold Shift during boot the loading bar only gets to 40% before it reboots.

Remaining options left are 1) boot from a Lion DVD and install Lion, 2) set the iMac to FW target disc mode and use the 2009 MBP to install El Cap, 3) run MemTest to test the RAM. The RAM modules run fine in a MBP though.

Question: How to I run those Apple hardware diagnostics that I see mentioned in some threads?

 

[jerwin]

Question: How to I run those Apple hardware diagnostics that I see mentioned in some threads?

https://support.apple.com/en-us/HT201257

 

[Bradamante]

Booting from a Lion DVD worked. However it then restarts the machine after the first phase of copying data, and then the second phase crashes immediately. I don't even get the progress bar, instead it freezed with the Apple logo and the spinning wheel before that.

To my knowledge around the 70% mark of the progress bar the graphics card is coming in. I have no given the graphics card to somebody who claims he can repair it by BGA soldering. I have also ordered a new VSync cable on EBay. We will see how this works out.

I am still a bit confused though. When I boot from the MacBook Pro via FW target disc mode the booting works. So it might also be the PSU. But then again how likely is it that both components (GPU and PSU) fail both at the same time? And if it was the PSU why can I boot at all?

 

[Bradamante]

The iMac is up and running now. I did three things: 1) exchange the vsync cable, 2) repair the GPU via BGA soldering and 3) trying different setups for the RAM. The vsync cable had to be replaced anyway. The GPU I repaired because I know that around 60-70% of the booting phase something happens with the graphics, I assume the drivers are being loaded. Similiar to what you see on a hackintosh. Putting in the repaired GPU got rid of the reboot loop where the iMac rebooted at 60-70% of the boot progress bar.

When I started experimenting initially (I bought the iMac used) the RAM worked with the default 2x 2GB. At some point however I noticed that one of the two 2GB modules was not recognized. I experimented a bit with the four slots and noticed that whatever I put onto the right side slots (with the display pointing upwards) is not activated. When I upgraded to 8 GB I put 2x 4GB into the left side slots and now it seems to work fine. The RAM arrangement was the actual breakthrough and for the first time the iMac booted through. I guess that allows for a maximum of 16 GB RAM (2x 8 GB on the left side) but not 32 GB (4x 8 GB).

MacsFanControl works fine to keep the HD fan in check after the SSD upgrade.

So overall the upgrade was successful. It just was far more expensive than it should have been.

The multicore Geekbench result however was a bit disappointing for me. I was hoping for 10K but did not even get 8K? With a i7-860? But yeah, this result is on par with other 2009 iMacs on Geekbench.