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Display is dim and will not brighten

Display is dim and will not brighten

The image on the display of my MacBook Pro A1278 is very dim. I'm not sure but I don't think that it's the backlight since the image is visible enough that the laptop can still be used but the screen lighting is very dim. The brightness adjustment on the F1 and F2 keys do nothing when either one of them is held down. The brightness adjustment in the System Preferences doesn't do a thing to dim or brighten the screen image. Is this a common problem and is there a fix for this problem.

Asked by: Guest | Views: 113
Total answers/comments: 5
bert [Entry]

"Don, first I must admit that I am not a Mac person. So this answer is a general answer and hopefully the Mac Guru's can help you out further. Since you already replaced the LCD with a working one, it is possible that this is caused by a bad inverter. Try to connect an external display and see if that works. If so, then it is the inverter/backlight circuit of your computer. If it does not, then you are having GPU trouble on your computer. Apple suggest:"" No display or dim display, but computer appears to operate correctly and has video operating on external display (display is fine after startup, but after a few seconds no display or dim display)

1. Remove any connected peripherals.

2. Try known-good power outlet, power adapter, and power cord.

3. Press F2 (with the fn key pressed and not pressed) to increase the screen brightness setting.

4. Reboot the computer—hold down the Control and Command keys and press the Power button, or press and hold the Power button for 5 to 10 seconds to shut down the computer, then press the Power button to restart.

5. Reset the SMC. See Knowledge Base article 303319, “Resetting MacBook and MacBook Pro System Management Controller (SMC)”. Resetting the SMC means you will also need to reset the date and time (using the Date & Time pane of System Preferences).

Warning: Make sure you do not hold down the “fn” key when resetting the SMC.

6. Reset PRAM. Restart the computer, then hold down the Option-Command-P-R keys until you hear the startup sound at least one additional time after the initial startup sound.

7. Connect an external display, and check for video on external display.

• If video is fine on external display, troubleshoot LCD panel and verify cable connections to inverter and LCD. Verify battery connector with sleep switch connection.

• If video symptom is same on external display, replace logic board.

8. Verify that LCD panel cable and LVDS cable connections are seated properly and that the cables are not damaged. Check cables around the hinges for damage.

9. Replace Inverter board.

10. Replace battery connector with sleep switch.

11. Replace LCD panel.

12. Replace logic board.

If the numbers are right, then you have a fuse for your backlight on your logic board. It is a 2AMP-32V SMD fuse. Test it with a multimeter and see if you have continuity. If not then you need to replace that. Hope this helps, good luck."
bert [Entry]

"I had this issue after replacing the screen on my late 2013 Macbook Pro. I opened up the machine again and reseated all the monitor related ribbons/cables that I touched during the replacement and it now works!

Before you open up the casing again, try closing the lid (to sleep) and re-opening. Weirdly this can work."
bert [Entry]

Yesterday my Mac was also doing that I have tried everything like pram vram smc and then with frustration removed battery and opened its back cover with screw driver. Unplugged all tiny mini cables n given some heat with heat gun replugged all cables fixed its back cover and now my MacBook is running perfectly. Remember guys i suggest u to do all these things very carefully. u don't need to pay for repair because we can solve these tiny mini problems
bert [Entry]

If all the above fails, use a magnet and move it up and down along the sides of the monitor. Tell us know if this works as you have a sleep switch issues.
bert [Entry]

Have you tried to close the lid then open and adjust the brightness of the mac??this happens in my macbook pro mid 2014, i dont know if its a system bug or a problem with the logic board due to that this was a replaced one.