Chosen Solution

My MacBook A1278 Screen intermittently goes dark. I can see that the display is still working with a flashlight. If I press the brightness buttons I can see that the increase/decrease bar is working.

  • This model does not have an inverter as it is LED lit
  • Because I can see the display working, I assume that the logic board and drivers are good.
  • I am guessing that the intermittent part eliminates a problem with the WLED fuse on the on the logic board not supplying power to the LED, and perhaps the LED itself. So??? LVDS cable?? Other possibility?? If cable, is this replaceable?

The LCD its self is likely OK here. The logic board has the power circuity for the LED backlight and it could need repair. But, first lets see if the data cable is OK. Does the backlight wink on and off when you tilt the lid or press on the display? If it does then you likely have a bad cable. Review this IFIXIT guide Replacing MacBook Unibody Model A1278 LCD Panel In this case we need to get to the cable on the LCD and logic board to replace it From the Apps store download Temperature Gauge or some other like monitoring program. With it running see what the temp of the display is when the backlight goes out. Then try lowering the screen brightness does the backlight stay working longer and is the temp lower? If it is then you may have a bad display (the LED backlight part of it). If it winks out with no movement at any brightness then your problem is on the logic board and you will need to review the backlight power circuit. You likely have a cold solder joint on one of the power FET’s.

In step 9 of the LCD display iFixit report for the A1278, I removed and then used tuner cleaner spray on the cable connector and the cable end going from the motherboard to inverter/display cable. It seems to have fixed the issue. Sure beat tearing the display apart!

might be the sleep sensor problems…just check the connection…! id tried this link,and fixed (just the connection loose) MacBook Unibody Model A1278 Hard Drive Bracket with Sleep Sensor Replacement