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My late 2015 iMac A1419 (EMC 2834) went black a few days ago. I removed the display and see the first two led lights on but not 3 and 4. I do NOT hear any chime but the fans spin up at high speed. I’ve tried an external display and get nothing. I’ve tried PRam reset and I’ve tried removing ram sticks. Same thing every time, no chime, lights 1 and 2 on, nothing else. Any ideas?
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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.
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Thank you, although mine is not making any chime. What does that indicate?
Try zapping the PRAM on start up
How to Reset PRAM or NVRAM on a Mac
Shut down your Mac.
Press the power button.
Before the grey screen appears, press the Command, Option, P, and R keys at the same time.
Hold the keys until your computer restarts and you hear the startup sound a second time. ...
Release the keys.
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You can get more information from this post
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Thank you but this doesn't solve my problem. I understand the order of the LED's but I don't know what is causing my 3rd LED to not light up
If that problem happened with no reason, your diagnostic leds are saying that there is a problem with your video card or display, you said that you already tried connecting a external monitor and i cant see anything, ending with a VIDEO CARD FAILURE .
i have the same issue. after i install cpu incorrectly and cpu its bent .so i make it flat now .work but without image and some of part(Capacitors,filter .. ) are missing on logic board in part where are ram... any help? or any donor board mid 2015 i will pay shipping
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No chime, LED 1 and 2 on. No others illuminated.
I got this error. I do it this way:
Press and hold the SHIFT button and then press the POWER. The iMac will start up with a sound and screen. Good luck. Chúc may mắn!
由 Mia Palo 完成的