I'm trying to fix an iMac.. with Windows

[bANONYMOUS]

Title says it all, I'm trying to fix an iMac, by installing Windows ..and ONLY Windows.

 

I got this for the wife (aesthetic is everything), it has a failed hard drive and because every Apple repair cost more than a luxury car, I picked it up super cheap.

So, I'm trying to "fix" this by removing the rotten apple inside, and you know ..opening a windows... Pun intended.

 

Now to start, it's an A1312 mid-2011 27" iMac12,2 with the i5-2500S with 4GB (2x2gb) PC3-10600 RAM, failed/failing 1TB HDD (still boots but locks up completely after a few minutes), and currently has macOS 10.13.6 which is the last supported OS. I can't use dosdude1's patcher because of the AMD 6770M 512mb GPU being unsupported on 10.14 and later for lack of hardware acceleration.

 

I was in there replacing the HDD, and I got kind of carried away. I had an old 2TB HDD from an old build just sitting around, which was just going to be the "free repair" but then a 256GB SSD caught my eye and some other parts to make my own Fusion Drive kit just like the one iFixit sells, so now it has a 2.25TB Fusion Drive and a clean install of macOS 10.13.6.

 

My next concern was the factory installed 4GB of RAM, I checked out the specs on everymac.com and it says it can support up to 32GB, so I did some more digging around in all of my spare parts and was able to find four matching 8GB modules, so now it has 32GB of RAM just from spare parts I had laying around.

 

I originall installed macOS 10.13.6 back on it to used bootcamp to download the windows support files, saved that to an external HDD. I then installed Windows 10 64-bit, wiped everything on install, only Windows, no macOS, on first boot I manually installed the drivers from the bootcamp files saved on the external HDD (not using the bootcamp drivers setup), one driver at a time to avoid Apple infused bloat (reboot to macOS button, etc).

 

First issue, aside from everything working "perfect", but the keyboard controlled brightness and the on-screen brightness indicator goes from min to max and vice versa without issue. But the illumination of the display doesn't do anything, always stuck on full brightness. Given that these generations of iMac's suffer from LCD Inverter board failure when they're left on full brightness for too long, I didn't wanna play this game on russian roulette.

 

Second issue is it will not wake from sleep, if the screen times out and goes black, it's game over, needs a hard reset, currently have the screen set to never turn off so it's completely usable right now, but like mentioned, they're known for the LCD inverter board failing from the brightness being on full all the time so I just make sure she turns it off after every use. Not a huge issue with the drastically improved boot time from the Fusion Drive, but still annoying.

 

In short, these two issues are literally just screaming for that display backlight to fail because the brightness is stuck on full, and the display won't turn back on if it goes to sleep haha.

 

Any suggestions are greatly appreciated.

[bANONYMOUS]

I'm single now, so I'm going to try and look into this iMac again. It's been almost a year since I made this thread. Since posting this I did figure out a "solution" but it wasn't a very great one.

 

Basically to put this blunt, you CAN'T run Windows 10 on this model of iMac, it's an issue with the GPU. That's probably why Apple only officially supports Windows 8.1 as being the highest supported OS for Bootcamp.

 

So I just ended up wiping this and reinstalling macOS 10.13.6 and she used it like that to finish her degree, now that I have it back and she's gone. I need to get my mind off crap so I'm going to take another look at making this thing cool.

 

This is what I figured out so far.

 - Windows 10 will not adjust brightness or wake from sleep with the AMD 6770M or 6970M

 - This model of iMac CAN have the GPU upgraded to a 780M or 880M (and some other's but those are the two most stable options)
 - If I can find a good price on a 780M or hopefully an 880M, I just need to find the three pipe heat sink from the AMD 6970M model 2011 iMac because of the

 - My model having the AMD 6770M has the two pipe 35w TDP heat sink

 - The AMD 6970M model has the three pipe 75w TDP heat sink

 - The 780M and 880M are both 122W TDP chips

 - Other reports online have successfully installed the 780M and 880M with the 6970M cooler using better thermal compound without issues

 - The 780M and 880M just need a BIOS flash to be supported on the iMac and they are out of the box functional, everything works like it was OEM.

 

Since I'll be in there upgrading the GPU to one of those models, depending what's cheaper. I'll have the entire motherboard out anyway, so I might as well upgrade the CPU.

 - The i5-2500S can be upgraded to an i7-2600 as it was officially supported and all of the CPU heat sinks for this model are the same so I won't have issues there.

 - The i7-2600 is literally a direct plug and play upgrade, no flashing, no tweaks, just drop it in, use some quality thermal compound and it'll actually be better than factory.

 - I did find that the Xeon E3 1275 V1 is almost identical, both Sandy Bridge, both 3.4GHz base clock, both turbo to 3.8GHz, both 95W TDP

 - I just can't find anything so far as to whether or not the Xeon E3 1275 V1 will drop in without any issues just like the i7-2600 will.

 

From benchmarks online, the Xeon E3 1275 actually seems to perform better than the i7-2600 due to better power management and improved iGPU efficiency

On average the i7-2600 uses 114w and the Xeon E3 1275 uses 77w, as well as the Xeon having HD 3000 iGPU, where as the i7 has HD 2000 iGPU

 

So now comes down to price.

I found an i7-2600 on eBay for $110 CAD and the Xeon E3 1275 V1 for $75 CAD

I found the 780M for $250 CAD and the 880M for $315 CAD

 

Now these are my options

 - $325 for the Xeon with 780M

 - $360 for the i7 with 780M

 - $390 for the Xeon with 880M

 - $425 for the i7 with 880M

 

My baseline upgrade here is the $360 for the i7/780M, because that's a guaranteed working upgrade, and I don't really want to spend an extra $65 to upgrade to the i7/880M.

However if I can figure out if the Xeon will work without any issues (every function working, don't care if there's more work to making it work, it just needs to work)

Then I would be looking at only a $30 upgrade to the Xeon/880M which has better performance from both the CPU and GPU for only $30.. sign me up for that.

 

On a completely different note here, once it's been upgraded to either Nvidia GPU, it will support dosdude1's patcher so I can upgrade this to the latest macOS 11.00 as well as Windows 10 64-bit, run both on a 50/50 partitioned fusion drive so each OS would have a 1.25TB partition and this would actually be a pretty deadly computer.

 

Oh and my build tally so far is that I bought the iMac for $100 CAD because it was quoted at a local certified Apple repair shop that it would be around $500 to replace the hard drive, plus the cost of the drive depending on which one we wanted to install, save money and downgrade, replace the factory capacity, or upgrade. So this is a $100 iMac, the SSD and HDD were free to me because they were just old ones that I removed from other builds and just kept around as spare parts.

All of the cables and adapters for the Fusion Drive kit I put together myself using old spare parts I had laying around, and the 32GB of RAM was again just old parts I had laying around from broken laptops. The RAM kit I used was actually ordered for a customer, and when it arrived she said she just bought a new laptop so I was just stuck with the RAM but she gave me her old laptop as payment for the time I had already put into it. so I just put a cheaper RAM kit in the laptop and sold it second hand and made all of my money back on the new kit, so that was also free.

 

Realistically, this is a $100 iMac that's going to be a pretty good computer for either $360 with the i7/780M, or even better with the $360 Xeon/880M upgrade.

Either way, this is a sub $500 CAD iMac and in the end, I just need this project to get my mind off of everything.