off the diagnostic led 1
how it’s possible to be off the diagnostic led 1 on my imac and still open??? the 3 others led are on…its starts but has bad graphics after login screen.please somebody explain me…
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Because your system has two graphics systems one built into the CPU and the other is the dedicated GPU.
If you boot up within Target Disk Mode you should see the FireWire Icon on your screen. If you boot up under Safe mode you should be able to see your display using Intel’s Iris Pro graphics services within the CPU.
Update (08/01/2019)
Whats confusing here is your question is a somewhat backwards. I'm going to assume the real question is your #1 LED is on but the others are all off. As per this breakdown of the onboard diagnostic LED's:
LED 1 - Indicates that the trickle voltage from the power supply is detected by the main logic board. This LED will remain ON while the iMac is connected to the AC power. The LED will remain on even when the computer has been shut down or put to sleep. The LED will turn off only if the AC power is disconnected or the power supply is faulty.
LED 2 - Indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is working correctly.
LED 3 - Indicates that the computer and the video card are communicating. This LED will be ON when the computer is communicating properly with the video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the video card might be installed incorrectly or need replacement.
LED 4 - Indicates that the computer and the LCD display panel are communicating. This LED will be ON when the computer is turned on and video signal is being generated. If the LED is ON and there is no image on the LCD display panel, the LCD display panel or inverter might be installed incorrectly or need replacement.
I would replace the power supply iMac Intel 27" EMC 2309, 2374, 2390 or 2429 Power Supply following this guide iMac Intel 27インチ EMC 2309と2374の電源の交換
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So you think that maybe is a problem on logic board or no;
So what happened? Did the system startup as I has said it would? Are you able to boot up under Target Disk Mode? Are you able to start up under Safe Mode?
Until you tell me I can't tell where the problem is.
Hey and sorry for delay... No boot at all...
I have changed the power supply but still nothing... I thing maybe it's the logic board... Because I had problems with ethernet and the DVD before imac crash...
The it sounds like you had a power surge or lighting hit which killed your power supply as well as the logic board.
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Hey Dan! I have replaced the logic board and thw power supply, and i m trying to set up the ssd with the original DVD mac os x 10.0.2 but i get an error … and the process stop.
any suggestions?
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If you've replaced the GPU at this point then you have an issue with the clocks settings thats messing you up. Apple sets an expiration date within its OS so when trying to load older versions you often hit this. You see your clock is likely being set to to todays date 2019 where the OS installer requires the systems date to be back at OS-X 10.0.6 date window 2001 - 2005.
Are you sure you have this old an OS-X? You are more likely to have OS-X 10.6.2 Mountain Lion. You'll need to alter the date within the systems clock. Using Safe Mode you should be able to gain access to the control panel to back date the date after altering it from auto to manual setting. Here's how to do it within Terminal hanging system date from Terminal – OS X recovery
Frankly, you should just jump to macOS 10.12.x Sierra. You'll need to setup an external FireWire drive as a bootable drive with the OS installer file following this guide How to create a bootable macOS Sierra installer drive While your system can support macOS 10.13.x High Sierra I would not run it as it has a few issues that Apple has not addressed.
If you have a second system an alternative way is to use Target Disk Mode connecting your two systems together and then installing the OS this way Understanding the Applications for Target Disk Mode
Yes you have right.. The os is 10.6.2... Everything works and I will try to update to sierra tomorrow.. Also I must set the SSD fan that propably not works on that os.. Because it's soooo loud!
well after i replaced logic board, sata cable that cause problems, power supply and i bake the gpu , and i set up an new ssd samsung evo 840, i have installed yesterday the mac os el capitan and what a MIRACLE!!! it's works like a brand new!!!! i don't know for how long but it's seems that will works for long!
Thanks Dan for all your help and patience!
