EMC 2742 late2013 , iMac 21.5 LCD ON, LED-backlight dark flickering
Hi,
I have a 21.5'' Late 2013 iMac Model A1418 (EMC 2742) , that was sold in JAPAN.
Display’s backlight doesn’t work now, When you look carefully, the thin liquid crystal display is shown.
Now, I’m testing: Thunderbolt2(edited from 3) to HDMI external display
So, How to check for broken parts?
What is the probable cause of this type of failure?
Where on the logic board is the fuse element for the backlight?
My son's MBP has the same symptoms and repaired the logic board, by Apple U$D450.
Are there any method for below,
What should be input to the terminal of the display power connector to light the backlight? for always LED backlight-ON use I will... If I can do.
Thanks
Update (03/01/2019)
Thank you Dan,
This is the screenshot of connected external display (TB2 to HDMI adapter to ext. Dell Display)
This is screenshot re-conect ORG back-light darkdown display de-touch Ext.display DELL. It looks LCD Montor sensor is Allive.
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diagnostic
Shutdown Reason,Fan Diagnostics,Sensor Diagnostics,Battery Health
Normal,The fan appears to be working properly.,Temperature sensors appear to be working properly.,This Mac does not have an internal battery.
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I tried to video-record "stage lighting effect" , there was no again bright of display.
However, another case incident was happen "flickering falsh and very dark" , Please see Uploaded Video.
When flickering, the brightness is differnt than Backlight-”off”, It was ON very small darkness.
This is more and More dark than normaly minimunum dispray brightness adjust (I feel about 1% as normaly brightness).
In the video, I am pushing the button, but I feel it is timing unrelated to flicker.
The video was recorded brighter than I saw with my eyes.
Flickering does not last forever.
Flickering did not happen after this recording, display kept very dark.
When "stage lighting effect" at once time ago , display LED worked normaly brightness about 50%.
The currentry flickering & brightness of LED-bucklight.
Where does this symptom occur when something is wrong?
Is this a good question?
3 Comments
外部ディスプレイは機能しますか?
ある時点でディスプレイアセンブリを取り外しましたか?
Does the external display work?
Did you take the display assembly off at some point?
by Dan
Thanks,
Now, External display is working well but slow response.
ThnderBolt-HDMI to external display SONY
After LED back-light lost, I took off Orginal display as Two connectors from logic-board for find SONY display.
few times restart iMac , then clean installed old OSX, then
Now working on Mojave.
Few times switch display .ORG 21.5 & SONY and both display , or AppleTV.
by Mit SUZU
アプリをインストールするTG Proメインウィンドウのスナップショットを撮ってここに貼り付けると、Adding images to an existing question が表示されます。
Install the app TG Pro take a snapshot of the main window and paste it here for us to see Adding images to an existing question
by Dan