Model A1311 / Mid 2010 / 3.06 & 3.2 GHz Core i3 or 3.6 GHz Core i5 Processor

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After HD changed, fuse (wall) tripped, no internal video, but external

Hi everybody here,

I just read a lot about diagnostics LEDs here and will give them a try when I have access to my iMac in trouble, again. Maybe, someone can help me out, quickly.

After replacement of the HD and powering the iMac on, the fuse of the electric circuit of our basement was tripped. After inserting the fuse again, the iMac started up without any signal on the display (black, no fragments viewable using a flashlight).

The iMac works properly with an external display. However, System Preferences -> Displays does only show one display - the external one.

I tried another display/video cable-combination of another iMac (same model). This does not work either with the problematic iMac. But the display/video cable-combination of the iMac in trouble works perfectly when it's installed in the other iMac.

The LVDS-connector on the logic board seems to be OK. I haven't tried to use another inverter board or power supply, yet.

I found someone who would solder a new LVDS connector, but it's quite expensive. Shall I give it a try? What do you think?

Best regards

Answered! View the answer I have this problem too

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What does it mean, if LED 4 stays off?

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Chosen Solution

The logic board needed repair: inductor L9000 was burned:

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This is a detail of the circuit diagram:

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When the inductor was replaced, the internal screen started working again. Hooray!

Some had trouble to locate the inductor. Here is an image that should be helpful:

Block Image

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Thanks a lot, was looking for that to finally solve my problem! Mit freundlish Grüßen von Brasil!

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Most Helpful Answer

Use a flashlight held at an angle to the screen (with the machine booted up), and see if you can discern the desktop. We're checking out the LED driver board. If the desktop is there we then want to make sure of your exact model

A, to get you to the correct part and guide,

B. To make sure it's not a bit of an older machine with an inverter.

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Thank you for your reply, mayer. As I wrote above, there is no login screen, no desktop, no grey Apple on the internal screen - not even unlighted:

(…) the iMac started up without any signal on the display (black, no fragments viewable using a flashlight). (…)

Is the LED driver board responsible for the backlight only? I assume, the problem ist with the electricity supply of the display: No power for the display -> the display cannot signal its presence, right? It would make sense for the internal display not showing in "System Preferences" -> "Displays", then.

I would be quite happy, if the problem could be solved by an new LED driver board for it's much cheaper than a logic board…

Best regards

Olaf

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Hey Olaf. Mind telling me how you replaced that inductor? I think I may have the same problem.

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I'm sorry, Paul. I did not repair the Mac myself. It must be done by someone having experience in SMD soldering. Regards, Olaf

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I figured that was probably the case. I opened my iMac last night and hunted around on the logic board for the L9000 inverter. I couldn't find it anywhere. Mind sharing the location?

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Maybe the inductor is on the backside of the board. If so, the board must be removed to find the inductor. Be sure, you have exactly the same iMac. This ist ten name of the schematic diagram: apple-imac-a1311-k74-mlb-0518337-8202784.pdf

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Hi @multifinder I have the same problem here.. where I can find the inductor?

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Part L9000 is under video card on back of logic board. Black plastic insulation covers it.

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Olaf will be eternally grateful.
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