Looking for a fix for my Imac

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
I have clean, high end IMAC that I rescued from a trash dumpster. It has a cracked LED screen that doesn’t work. The machine does boot hooked to a secondary monitor. The hard drive is a Samsung Pro SSD 250 GB which has been wiped. I have attempted to load El Capitan from a USB stick and Mountain Lion by internet recovery. Both attempts resulted in the video signal ceasing and subsequently ending in sleep mode on the monitor after about 20 minutes of the install process.

My question is… am I doing something wrong…is there a setting that needs to be changed or do I have a bad video chip on the logic board? Frankly, I suspect the latter!

Please don’t tell me to take it back to the dumpster…..LOL!

Here are the specifications on the IMAC:

Late 2012 model 1418/EMC 2544 2.7 GHz i5 CPU with 8 GB DDR3. Serial number: #C02KW6PRDNCR
 

nambuccaheadsau

macrumors 68000
Oct 19, 2007
1,835
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Nambucca Heads Australia
Sounds like it was in a dumpster for a reason.

Maybe it has had a drop or something. At least you got a good (if you dare call anything Samsung good) SSD out of it. With the thumb drive in place, does it actually boot from the thumb drive?
 

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
Sounds like it was in a dumpster for a reason.

Maybe it has had a drop or something. At least you got a good (if you dare call anything Samsung good) SSD out of it. With the thumb drive in place, does it actually boot from the thumb drive?[/QUOTE

Thanks, I stumbled on to the fix late this morning. The issue was the machine going to sleep during the OS install….so I rebooted the system and did the internet recovery mode again with a key on the keyboard taped down. This kept the machine busy and Mountain Lion installed without a hitch. I would assume you could work the mouse for a hour or so and have the same result. Regardless, now I have a very nice iMac for the cost of the cracked replacement screen.
 

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
Update: Upgraded ML OS to Sierra, installed trim enabler for third party SSD. Machine seems a little sluggish with 8GB DDR3 loading web pages and with multiple apps open on Desktop. I think I will order and install 16GB while I still have the system open.

I am experiencing the racing fan scenario, but suspect it relates to the sensor cable of the cracked LCD not being connected to the logic board.
 

MarvinHC

macrumors 6502a
Jan 9, 2014
762
222
Belgium
The high spinning fans are most likely the result of the aftermarket SSD install - use mac fan control to adjust it.
 

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
This model of machine doesn't have the temperature sensor and third party SSD issue. I hooked up both old LCD connections and restarted the machine about a hour ago.....the fans are now quietly running. So it obviously the fan issue must have been the LCD cables being disconnected from the logic board. Also surprising the machine isn't running sluggishly any more.....
 

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
The 21.5" model went to a slow 5400rpm laptop hard drive to overcome the heat sensor cable problems but it lost a huge amount of performance. You have solved that with the SSD.
yes, I believe you hit the nail on the head....the 5400 rpm hard drive was a huge mistake performance wise....

I should receive the 2-8 GB of DDR3 later this week and that should make it really fly changing applications and web pages. I can't believe I have to basically gut the machine to put in two sticks of RAM...how much would a access panel have cost on the back of the unit? I'm sure this was a marketing decision by Apple to make you buy an new IMAC down the road.
 

nambuccaheadsau

macrumors 68000
Oct 19, 2007
1,835
433
Nambucca Heads Australia
Not really it was a design decision.

As an Apple shareholder get some insights to these things and Apple research has shown that over 97% of folk buy their various model Macs and never upgrade or update them, in the majority of instances not even the operating systems. Just look at the number of threads folks using Snow Leopard on machines that could be updated to El Capitan, and even Sierra.

As a result the decision was reached to make the 21.5" iMac considerably less user updatable and the lack of external hatch was one of the first of these.

Also 2011 iMacs were quite easy to snap open using suction caps but things changed with the 'sticky' with the next model. So much so some Apple technicians and Resellers are extremely reluctant to work on them in case of damage to cables etc during the cutting procedure.

It would seem most Mac users are not like we more enthusiastic users. Just look at the garbage can so called Mac Pros!
 

1tomcat1

macrumors newbie
Original poster
Mar 3, 2017
24
0
nambuccaheadsau: I actually own two iMacs, a 2011 A1314, i7 CPU and a late 2012 A1418, i5. The older unit is completely functional and running El Capitan. The newer unit works with a exterior monitor and as you know I am trying to remedy some LCD issues likely related to a damaged cable.

The design of the two units is somewhat similar except for access to the internal hardware...the older unit has straight forward access with the thicker body. The newer unit with the thinner body and sticky taped LCD requires more patience and skill to open. I prefer to work on the 2011 and older units for the obvious reason. I have successfully opened several other newer units using the guitar pick method described in the OWC video without any problems, so it does work as long as you are careful and don't rush the process. Most people get in trouble by cutting too deeply into the machine or cracking the LCD when prying it off the body....

I share your views on the garbage can, mac pros...they don't appeal to me!
 

nambuccaheadsau

macrumors 68000
Oct 19, 2007
1,835
433
Nambucca Heads Australia
I have a friend who is an Apple Reseller in Sydney. His technicians will not crack the +2012 iMacs of any flavour. They hand deliver them to Apple's workshop the other side of the city. After five or six broken screens, he lets Apple worry about new hard drives, etcd.
 
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