iMac Intel 27". EMC 2309 (Late 2009, Core 2 Duo 3.06 or 3.33 GHz), EMC 2374 (Late 2009, Core i5 2.66 GHz or Core i7 2.8 GHz)

350 Questions View all

iMac A1312 BLACK SCREEN

Hello guys!

I have an iMac A1312 27"

It was working properly but NOW it turns on make the Apple CHIME. but SCREEN is totally DEAD (NO VIDEO).

At first I tought it was the POWER SUPPLY for the LCD. I changed it with a brand new ONE. NOTHING HAPPENED.

Then I started to think that it is related to the connector on the logic board and I am thinking right now to REFLOW it. What do you guys thinks?

I heard that it may be the GRAPHIC card. BUT when I use the THUNDERBOLT to an external display it works fine.

The computers works 100% fine but dont GIVE image to its own LCD.

Sometimes I think there is no energy going through the LCD cause if the CONNECTION from the LCD to the logic board is not good it stills could produce some energy like a MONITOR without anything plugged at it. DOESNT it?

PLEASE HELPPPPPPP!!

Answered! View the answer I have this problem too

Is this a good question?

Score 0

Comments:

Do you have a spare working screen around to test? Usually is the screen on this model.

by

@angelorecaman You appear to be repairing Apple products professionally. Would you mind expanding your profile so we can get to know you better?

by

@mayer

What kind of info do you need? On the menu MY PROFILE nothing that I need to update!

by

You are correct Angelo, after looking over your questions I know all I want about you. @oldturkey03 may be more able to help you than I. Mike what do think of our Sanguisugæ OP?

by

Hi,

did you get solution or not yet,I have Exactly the same issue imac 27" 2011

by

Show 5 more comments

Add a comment

2 Answers

Chosen Solution

I'd start by following Deep dive suggestions from Apple but would stop at #7

Deep Dive

1. Verify boot chime present and fans running when computer powered ON. (Reset SMC and clear PRAM if necessary for proper boot up.)

Yes Power on self test OK.

Go to step 2.

No Go to Won’t Start Up symptom flow.

2. Verify if image is visible on built-in LCD panel, with adjustable backlight level.

Yes Video present. Verify system functionality and return to user or go to appropriate troubleshooting flow.

No Go to step 3.

3. Connect supported external display. Verify if image appears on external display when system is booted.

Yes External display detected by system. Video circuitry on logic board functional.

Go to step 4.

No Go to No Video symptom flow.

4. Verify if LCD backlight is ON by looking for faint glow from display when viewed in darkened room with brightness set at maximum.

Yes LED backlight is functioning.

Go to step 7.

No Go to step 5.

5. Shine bright (low heat) flashlight onto front of LCD. With computer powered ON verify if a faint image is visible.

Yes LCD panel functional but backlight is missing or dim. Remove LCD panel and inspect and reseat the

following cable connections:

-Backlight power cable

between backlight board and LCD panel.

-Vertical sync cable between backlight board and LCD panel.

-DC power cable to backlight board and power supply.

Replace any damaged cable.

Reinstall LCD panel and go to step 6.

No No image or backlight.

Go to step 7.

6. Power ON system. Verify if image is now visible on LCD panel with correct backlight level.

Yes Issue resolved.

No Replace LED backlight board.

Retest. If issue persists, go to step 7.

7. Inspect and reseat internal DisplayPort cable (between logic board and LCD panel).

Power ON system. Verify if image is visible on built-in LCD display.

Yes Issue resolved.

No Replace internal DisplayPort cable.

If issue persists, replace LCD panel. Run Apple Service Display Utility to verify the resolution of intermittent display flickering symptoms. If the Apple Service Display Utility fails, contact Technical Service Provider Support

Anything after that, you'd have to measure some voltages on your logicboard.

Was this answer helpful?

Score 4

Comments:

@oldturkey03

@mayer

I already tested everything and IT IS the display connector on the logic board. Do you have a video/tutorial that shows how to REPLACE it?

Thanks!

by

@angelorecaman you did not say that you had already checked that. Anyhow this video shows how to replace the connector https://www.youtube.com/watch?v=M4POV5jn...

by

Add a comment
This answer was originally to another question.

Try it with an external monitor. This model has issues with the GPU solder. Let us know your results.

Was this answer helpful?

Score 2

Comments:

@mayer

I already tried with an external monitor and it works 100%, so I guess it is some issue related to the LCD.

IMPORTANT TO MENTION

-Tested with a NEW LCD,

-Tested with a NEW INVERTER

NOTHING WORKED

BY NOW

What I am assuming is that something RELATED to the inverter is not working. Cause if was the LOGIC BOARD CONNECTOR the LCD should turn on and bright even in a glowing dark image. but it seems to be DEAD no energy at all.

Since I already tried a new INVERTER I am starting to think it is something related to the CABLES that bring energy to the INVERTER.

What do you think?

by

@mayer

What do you think?

Actually I already TRIED new cables. Shouldn´t the LCD glow if the inverter is ok but the LOGIC BOARD connector is not?

by

Not if you have issues with your Panel power control circuitry.....

by

Add a comment

Add your answer

Angelo Recaman will be eternally grateful.
View Statistics:

Past 24 Hours: 1

Past 7 Days: 11

Past 30 Days: 72

All Time: 411