Model A1419 / Late 2012 / 2.9 & 3.2 GHz Core i5 or 3.4 GHz Core i7 Processor

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Why I have no power to screen?

I just bought a 2013 iMac 27. I was told that the screen and LCD needed replaced. I done the replacement and I'm still not getting any power to my screen. What other potential issues would I have before I do a full year down of the iMac. Any help would be greatly appreciated in this.

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Does the computer power on and work with an external display?

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What size is your iMac? We can't get youth the correct guides until we know your exact machine.

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iMac powers up but no external display. Model is a 1419.

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See what the diagnostic LEDs are telling you:

The LED's are on the logic board to the right of the RAM slots and between the RAM slot and the HDD sata connector

LED #1

Indicates that the trickle voltage from the power supply has been detected by the main logic board. This LED will remain ON whenever the iMac is connected to a working AC power source. 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 source 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.

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Does the iMac power on at all? The power supply is probably bad, if there is no power at all. If there is power and nothing is displaying, you could have a bad gpu on the logic board.

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