Model A1418 / Late 2012 / 2.7 & 2.9 GHz Core i5 or 3.1 GHz Core i7 Processor

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diagnostic lets are still dead any assistance?

Hi I have an issue the with the same model iMac no power. i changed the power supply with brand new one and the diagnostic lets are still dead any assistance ?

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I think it might be the logic board, sorry :(

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if the power supply is good, the #1 LED will come on. What was your part source?

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Check you power cord as well as the outlet you are using. Are you sure both are good?

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Power cord and outlet has voltage

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I'm sorry but I still believe you got a bad power supply.

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If you are even getting trickle voltage with a bad power supply #1 LED will be on.

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.

Recheck your installation: iMac Intel 21.5" EMC 2544 Power Supply Replacement

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I did and i am currently working on it with the logic board and power supply setting on my my desk and still no diag led. could assist me with finding a repair manual with the necessary test point ?

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Nathaniel Mcintosh will be eternally grateful.
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