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

Question

iMac Intel 21.5" EMC 2389

Modelo A1311 / mediados de 2010 / 3.06 y procesador Core i3 de 3.2 GHz o procesador Core i5 de 3.6 GHz

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Olaf @multifinder

Rep: 193

6

2

Publicado: 11 de mar. de 2016

Opciones

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

Contestado! Ver respuesta Yo también tengo este problema

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Puntuación 3

1 comentario

What does it mean, if LED 4 stays off?

16 de mar. de 2016 - de Olaf

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5 Respuestas

Solución Elegida

Olaf @multifinder

Rep: 193

6

2

Publicado: 14 de abr. de 2016

Opciones

The logic board needed repair: inductor L9000 was burned:

This is a detail of the circuit diagram:

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:

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3 comentarios:

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

31 de may. de 2017 - de Cristiano Henrique

many thanks, you solved my problem !!

5 de feb. de 2018 - de pierre

Great stear on the problem found that the part was blasted to bit's an the telltale was a hole in the plastic cover . Replaced the part with some effort as one of the pad's had been burnt off. But the through plate was enough to create a good connection and now working. Model etc 2428 i5 16GB 500GB

13 de feb. de 2020 - de mark scott

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Thanks a lot, was looking for that to finally solve my problem! Mit freundlish Grüßen von Brasil! — Cristiano Henrique
Great stear on the problem found that the part was blasted to bit's an the telltale was a hole in the plastic cover . Replaced the part with some effort as one of the pad's had been burnt off. But the through plate was enough to create a good connection and now working. Model etc 2428 i5 16GB 500GB — mark scott

mayer @mayer Rep: 685.3mil MacHale Enterprises 3.4mil 1.1mil 2.6mil · Answer 1 · 2016-03-11T20:42:03-07:00

mayer @mayer

Rep: 685.3mil

MacHale Enterprises

3.4mil

1.1mil

2.6mil

Publicado: 11 de mar. de 2016

Opciones

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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1 comentario:

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

13 de mar. de 2016 - de Olaf

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