Late 2009 iMac works in safe mode only

[Sunil355]

My 27" late 2009 iMac froze the other day. Upon restarting it hangs at around 60-80% loading bar on the apple logo start screen.
I managed to login into recovery mode disk utility and duplicate my drive to recover data. I ran first aid and no errors showed up. Was still unable to access so I reinstalled the OS (High Sierra) using recovery mode. This finally allowed me access to safe mode. I trimmed all of the startup applications and uninstalled lots of apps
I was thinking of replacing the HDD with SSD. I tried installing fresh OS install on external HDD first to see if that would load before purchasing SSD. That also only boots in safe mode otherwise hangs at loading screen. This leads me to think the issue is not the HDD. (Ps HDD was replaced under recall at apple store a few years ago)
Mac feels very hot at the top too.
Any ideas on what the problem could be and how to resolve? Its in great condition and has served me well for many years so would be a shame to see it scrapped.

 

[zoom25]

Hmmm, hopefully someone helps you out with this particular issue. I also have 27" Late 2009 iMac w/ 12GB RAM and 1TB Evo SSD

I've had times where it stuck and I'd just plug the cable out for a few minutes without anything attached on the peripherals. I'd also reset PRAM, NVRAM, and SMC. If that doesn't work, I'd do a complete fresh install.

When I opened the iMac around 2 years ago to install the SSD, I spent quite a bit of time cleaning and getting all the dust out between all the various mounts and fans. Upgrading RAM from 4GB to 12GGB was also very much required. I could technically take out the original 4GB to replace it with 8GB to have 16GB maxed out, but I didn't find it necessary and didn't want to spend the money.

After putting the SSD in, I did a complete fresh re-install with the Snow Leopard that it came with. Then I went through few cycles of upgrades etc and got it upgraded to High Sierra 10.13.6, which is the furthest this iMac will go without any mods. Runs fast and quiet.

The experience in noise and performance between the SSD and HDD is worlds apart. High Sierra fully running from cold start in 30 seconds.

 

[Sunil355]

Hi Zoom25
Thanks for your reply. Yes I have reset the NVRAM, PRAM and SMC which has saved me in the past but this time no luck. I'm happy to do the HD upgrade to SSD if I'm confident it will work but as the external HD also only boots in safe mode, it suggests some other issue. Maybe I will open up and clean and see if that helps.
Thanks

 

[appltech]

Thinking that complete (from Internet Recovery Mode) reinstall macOS would help

 

[Fishrrman]

OP:

Does your iMac have a discrete GPU?
If so...
I'm going to guess that you have some kind of GPU problem or failure.

Reason:
When you boot into safe mode, the discrete GPU is by-passed and the computer boots with "integrated" (CPU-based, NOT GPU) graphics only.

Thus... you can get booted, up and running.

However, try to do a "regular" boot (which utilizes the discrete GPU) and... failure.

I could be wrong.

 

[Nguyen Duc Hieu]

My 27" late 2009 iMac froze the other day. Upon restarting it hangs at around 60-80% loading bar on the apple logo start screen.
I managed to login into recovery mode disk utility and duplicate my drive to recover data. I ran first aid and no errors showed up. Was still unable to access so I reinstalled the OS (High Sierra) using recovery mode. This finally allowed me access to safe mode. I trimmed all of the startup applications and uninstalled lots of apps
I was thinking of replacing the HDD with SSD. I tried installing fresh OS install on external HDD first to see if that would load before purchasing SSD. That also only boots in safe mode otherwise hangs at loading screen. This leads me to think the issue is not the HDD. (Ps HDD was replaced under recall at apple store a few years ago)
Mac feels very hot at the top too.
Any ideas on what the problem could be and how to resolve? Its in great condition and has served me well for many years so would be a shame to see it scrapped.

Replace the graphic card and it will work again.
You can't fix a hardware problem with software solution.
I experienced the same issue on iMac 2009 and 2011 (both 27"). Both of them hang in the middle of the boot process.
I replaced the graphic card and the iMacs booted normally.
I didn't bother with recovery mode of re-installing Mac OS, first aid or anything else.

 

[Sunil355]

Replace the graphic card and it will work again.
You can't fix a hardware problem with software solution.
I experienced the same issue on iMac 2009 and 2011 (both 27"). Both of them hang in the middle of the boot process.
I replaced the graphic card and the iMacs booted normally.
I didn't bother with recovery mode of re-installing Mac OS, first aid or anything else.

Thanks. Did you replace graphics card like for like or did you upgrade? If you upgraded what did you install and what upgrade options are there.
Thanks again.

 

[Nguyen Duc Hieu]

Thanks. Did you replace graphics card like for like or did you upgrade? If you upgraded what did you install and what upgrade options are there.
Thanks again.

On the iMac 2009, I replaced the HD4850m with a Quadro M4000m.
On the iMac 2011 (of a guy I know), I replaced his dead HD6770m with a Quadro K1100m.
On another iMac 2010 of mine, I replaced the HD5670m with a WX4150m.

 

[Sunil355]

On the iMac 2009, I replaced the HD4850m with a Quadro M4000m.
On the iMac 2011 (of a guy I know), I replaced his dead HD6770m with a Quadro K1100m.
On another iMac 2010 of mine, I replaced the HD5670m with a WX4150m.

Were these upgrades straight swaps or did they need flashing or some other procedure first in order to work? I currently have HD4850.

 

[California]

Were these upgrades straight swaps or did they need flashing or some other procedure first in order to work? I currently have HD4850.

For a 2009, replace the heat-making HDD with an SSD and see how it works. You'd be surprised how many problems a new SSD instead of your many-years-old-now HDD will fix.

 

[Nguyen Duc Hieu]

Were these upgrades straight swaps or did they need flashing or some other procedure first in order to work? I currently have HD4850.

Of course the cards need to be flashed with Mac compatible vBIOS.
It's the same procedure when you want to install an HP card to a Dell or Acer laptop, or vice versa.
Some small modifications on the hidden EFI partition on the booting disk as well.
But basically, the main volume of High Sierra is not touched. No need to do a fresh install of Mac OS and other stuff.

 

[pshufd]

We had this problem about six years ago but it was intermittent. So I put it in the basement for a few years. I wanted to get the data off the system and dispose of it so I booted it up and got the data off and removed the Windows partition and reformatted the drive with High Sierra. The thing is that the system worked fine for all of this. The basement is considerably cooler than the rest of the house in the summer and it appears that it runs fine in a cooler environment so it's been in use for about two years.

I just found a local 2011 iMac 27, 3.1 Ghz i5, 16 GB RAM, 256 GB SSD, Keyboard and mouse for $80. I put in an offer at the asking price because I'm a sucker for cheap iMacs. It may be more efficient to upgrade now that M1 minis and studios are killing used iMac prices.

 

[Nguyen Duc Hieu]

We had this problem about six years ago but it was intermittent. So I put it in the basement for a few years. I wanted to get the data off the system and dispose of it so I booted it up and got the data off and removed the Windows partition and reformatted the drive with High Sierra. The thing is that the system worked fine for all of this. The basement is considerably cooler than the rest of the house in the summer and it appears that it runs fine in a cooler environment so it's been in use for about two years.

I just found a local 2011 iMac 27, 3.1 Ghz i5, 16 GB RAM, 256 GB SSD, Keyboard and mouse for $80. I put in an offer at the asking price because I'm a sucker for cheap iMacs. It may be more efficient to upgrade now that M1 minis and studios are killing used iMac prices.

80$ is a very nice price to get an iMac 2011.

 

[pshufd]

80$ is a very nice price to get an iMac 2011.

They come up locally from time to time. I bought a 2010 i7 around January for $100 as the owners couldn't boot it up. These sorts of deals are usually very quick to go.

 

[Sunil355]

Of course the cards need to be flashed with Mac compatible vBIOS.
It's the same procedure when you want to install an HP card to a Dell or Acer laptop, or vice versa.
Some small modifications on the hidden EFI partition on the booting disk as well.
But basically, the main volume of High Sierra is not touched. No need to do a fresh install of Mac OS and other stuff.

Hi
I've never done this before. Is this difficult or is there risk of not being able to use the graphics card again? I've watched a couple of videos about similar things. Does doing this lose the boot screen and brightness control etc? Any good tutorials to follow.
I'm currently following a tutorial to bake/reflow the graphics card so trying that first before purchasing another Graphics card.
Also the replacement graphics cards are around £100 whereas a working second hand iMac could be around £150-£200 for a better spec.
Thanks ?

 

[Nguyen Duc Hieu]

Hi
I've never done this before. Is this difficult or is there risk of not being able to use the graphics card again? I've watched a couple of videos about similar things. Does doing this lose the boot screen and brightness control etc? Any good tutorials to follow.
I'm currently following a tutorial to bake/reflow the graphics card so trying that first before purchasing another Graphics card.
Also the replacement graphics cards are around £100 whereas a working second hand iMac could be around £150-£200 for a better spec.
Thanks ?

I did the baking/reflowing once at a laptop repair shop on my first HD4850. They had professional reflow station.
It didn't work. Same or even worse result.
Therefore when my second HD4850 halted the booting process, I just replaced it.
It helped me saved me some time and money (for not baking the dead card)