Imac 27 mid 2011 high sierra  Mac Mini

Setup as music production Rig?
MAC FAN
Move package into applicartions folder in order to upgrade.
Not whole dmg.
control s then
fsck
fsck -fy
sudo nvram boot-args=amfi_get_out_of_my_way=0x1
file sharing by smb works
the auto system is haphazard
smb://192.168.1.117  Eric nd
USE as AVirtual machine to access minimac as montor.
Try with linux
Try without Dropbox
Hard Drive Seemed to be complicit however
nvram fix is part of solution.
Time machine to be able to migrate backwards.
Make back up on time machine.
Install lion on computer to get back file sharing?
Many of the symptoms suggest memory issues.
Take memory out and try.
Memory Test
Found Isue  4sns/1/40000000 TH00-9.000
Fan control
OSX System Software Upgrades
Worth $220 repaired
Value: $375 loaded
27" Monitors $150
Options: Fix  $50  Part out: 200+ 

Use Safari to download upgrades to osx

Get software via safari at link on head of list
power cord  seems to have been issue
Downside... multiple systems in box
DVD player shaky
Relatively difficult to service but better than latter macs.
The connector for the screen temp is fiddly.
Large foot pirnt heavy prone to issues with power supply.
Pros Vide and sound built in.
Upgrading Macs

imac power supply issues seem to be main problem
Mid 2011 power supply amazon 310Watt
Ebay
Mac Fan to control fan when installing incompatable drive.




                                
$439 Via Refurbisher 3.4ghz 1 TB 24gb memory.
$620 Max
Every Mac
  • Resolution: 2560 by 1440 pixels
  • Info


Supports up to...
30-inch display (2560 by 1600 pixels) on an external display


Power Supplies
614-0501, 614-0476, ADP-310AF-B, 661-5310, 661-5468, 661-5972, 614-0446

Flimsy display cable593-1352 A


Boot from USB


Press and hold the “Option” key when you hear the startup sounds—this will bring you to the Startup Manager. Once the Startup Manager appears, you can release the Option key. Startup Manager will then start scanning your device for drives it can boot from, including your USB.
s

A better solution in my opinion is a minimac and another brand
high resolution monitor  such as. Eating too much time keeping going.,


Hard Drive Evaluation
Command S to boot into single user.
repair
/sbin/fsck -fy
Run untill there are no changes.
If not good you will get the volume was modified.
"Seems to be ok"

Loading Older Systems
All sata drives should work . 500gb entry level
Western digital RPM 7200
WD5001AALS


More Hard Drive Evaluation
Disk Drill
Look for 3.8

From Terminal



Ebay
Power Supply OK after ordering new.

Tested Working
30 Day Warranty

No warranty but inexpensive add protection plan
odyson
https://www.youtube.com/watch?v=yKD682dBbSQ
Aliexpress
https://s.click.aliexpress.com/e/_AAPvg9
All Ebay

614-0446, 614-0476, 614-0501, ADP-310AF B, PA-2311-02A


hard drive sensor seems to be out

Details:This model is powered by a 32 nm, 64-bit Intel Core i5 "Sandy Bridge" processor with quad cores (four independent processor cores on a single silicon chip, each with one thread). Each core has a dedicated 256k level 2 cache and all processor cores share a single 6 MB level 3 cache. It also supports Turbo Boost 2.0 (up to 3.7 GHz) -- which "automatically boosts the processor speed based on workload" (so if an application is only using one of the four cores it will automatically increase the speed of the core in use and turn off the unused cores).

Also see: How much faster are the "Mid-2011" Aluminum iMac models than the "Mid-2010" models?
X 10.6.6 (10J4026)X 10.13.x*
Details:*This system fully supports the last version of OS X 10.8 "Mountain Lion", OS X 10.9 "Mavericks", and OS X 10.10 "Yosemite" except for Power Nap functionality. It also supports the last version of OS X 10.11 "El Capitan" -- including Mac-to-Mac AirDrop and AirPlay Mirroring capability -- but no other advanced features are supported including Metal graphics acceleration. It is capable of running macOS Sierra (10.12) as well, although it does not support the Universal Clipboard, Auto Unlock, or Apple Pay features. Finally, this model is capable of running macOS High Sierra (10.13), and it supports HEVC (High-Efficiency Video Coding), but it does not support hardware accelerated HEVC. It is not compatible with macOS Mojave (10.14) or later versions of the operating system.

Additionally, please note that OS X "Lion" 10.7 and subsequent versions of OS X are not capable of running Mac OS X apps originally written for the PowerPC processor as these operating systems do not support the "Rosetta" environment. To run PowerPC applications on this Mac, it will be necessary to use Mac OS X 10.6 "Snow Leopard".

Also see: Which Macs are compatible with macOS High Sierra (10.13)? What are the system requirements? Which Macs support HEVC?