iMac A1224 screen issue

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iMac A1224 screen issue

I'm back and with another Mac issue 😝

Just picked up a 20" iMac from a customer who was suffering from a screen issue. My colleague thinks it might be popped caps and we're in the process of taking a look but I wanted to get others opinions as well.

Computer boots fine, chime and everything, boots to grey screen and then the screen goes black. We figured the screen was out, not just the backlight, so we're checking, as I said, for popped caps. Computer runs fine, I can hear the volume change 'pop' when I adjust the volume on via the keyboard, but I get nothing from the screen. Cmd + Opt+ Eject and then moving the mouse revives the screen for about 2 seconds before it goes black again.

Will update soon whether it was the caps or not.

iMac, Mac OS X (10.6)

Posted on May 6, 2013 2:29 PM

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Answer 1

nick.XIII Author

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May 7, 2013 6:48 AM in response to nick.XIII

So we didn't find any popped caps. we did, however, find some white residue on the PSU and under 2 caps on the other side of the motherboard, as well as possible signs of arcing or water damage on the backside of the power plug on the motherboard.

This is the back of the PSU, with the residue on the right.

https://docs.google.com/file/d/0B-xuEmFtE0dKbE1pZFhwcG82cG8/edit?usp=sharing

Closeup of the PSU.

https://docs.google.com/file/d/0B-xuEmFtE0dKUE1laHI2TmF0Nk0/edit?usp=sharing

Front side of motherboard, with the 2 caps highlighted, as well as the PSU plug.

https://docs.google.com/file/d/0B-xuEmFtE0dKMDdaMEQwYzlTQ1k/edit?usp=sharing

Backside with the backs of the caps higlighted. The one on the left is the blue one, and the right is the purple.

https://docs.google.com/file/d/0B-xuEmFtE0dKalpNYkltNm1Pak0/edit?usp=sharing

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Answer 2

nick.XIII Author

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May 8, 2013 6:31 AM in response to nick.XIII

Does anyone have any idea what's wrong with this iMac? BDAqua, rkaufmann87, anyone?

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Answer 3

nick.XIII Author

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May 9, 2013 12:29 PM in response to nick.XIII

Ok, well, we're planning on ordering a replacement inverter and resoldering the bad spots to see if that will fix the issues we are having.

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Answer 4

nick.XIII Author

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May 17, 2013 8:11 AM in response to nick.XIII

Well, nothing we're trying is working. 2 inverters and neither worked. Display came on, but not the backlight at all. We also resoldered all caps and the main power connector, no dice. Putting in the original inverter still does the original issue. At this point, we're thinking about junking it.

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