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Early 2011 model, A1278 / 2.3 GHz i5 or 2.7 GHz i7 processor.

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No External Video after PRAM Reset?

I call upon the IFixit Sages! I am recovering a friend's MacBook Pro 13" Late 2011 MD313LL/A damaged by spilled water. I know I put Early 2011 in the Device block above, but that is because all the internal parts are now from a MC724LL/A I purchased for parts to fix the MD313LL/A! As soon as I opened the water damaged MD313LL/A I found the Logic Board badly corroded and knew it needed to be replaced.

I tested the MC724LL/A and found it Option booted to Internet Recovery, but would not complete the process due to a bad hard drive. The Hard drive from the MD313LL/A did successfully boot without issues. That would solve the problem except for the broken right hinge mounting point on the screen and the dented mid-body just to the right of the Trackpad, making it impossible to click even though the cursor moved. I subsequently used this track pad successfully in the body of the MD313LL/A, replacing the water damaged one there that did not work.

I proceeded to replace the parts one at a time starting with the LB. I immediately discovered the LCD did not work and I had no video at all. I had a Thunderbolt External Video Adapter for external display. I purchased a replacement LCD display and after connected, I now had external video, but the MacBook Pro display still did not work. I also did not have working speakers. I performed a PRAM reset that restored audio, but now I no longer had keyboard backlight. I still considered that a win. I did not lose external video with this PRAM reset.

I continued replacing parts one at a time, but at each step I could only get to a Gray Screen with nothing else. I continued replacing parts one at a time without joy. After I replaced all the parts from the damaged MC724LL/A into the perfect body of the MD313LL/A and still could only get the Gray Screen I tried a second PRAM reset. This time I lost the external video. I have tried disconnecting the battery, SMC resets and numerous PRAM resets with no joy.

What can I do now? Did the LB fail? Did I somehow brick the LB? I hope there is a Wise IFixer out there that can lead me around this to finish the job or tell me it is hopeless and for me to move on. I also have USB Flash Drives with Lion and Yosemite on them that I used along the way as well, but they nor Internet Recovery would get me beyond the blank Gray Screen. On my first test of the MC724LL/A Internet Recovery, the MacBook Pro went a menu to reformat the disk, reload Lion and other choices, so I know what it should do for Internet Recovery after downloading the initial interface. Also, is there any way to test the LCD screen? I only have the word of the guy I bought the LCD screen assembly from that it works. I knew something was wrong with the original MD313LL/A LCD screen as there was no external video until I replaced it.

IFixit is great! I could not have gotten this far without the Guides here. I just hope there is some Wise person out there to take me home or tell me to move on as the issue cannot be fixed. thank you all in advance!

Ответ на этот вопрос У меня та же проблема

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OK after reading more on PRAM and SMC resets I found I was doing the PRAM correctly (Command, Option, P and R on starting chime, hold for 2 or three reboots then release and restart), but I was not doing the SMC reset correctly as I was disconnecting the battery and pressing the power button for 5-10 seconds. I found that for the MC724LL/A with a "user non-Serviceable battery" (come on Apple you have got to be kidding a tri-lobe screwdriver is not going to stop a reasonable person) you press Left Shift, Control and Option at the same time as the Power Button, release after 5-10 seconds then press Power to start. This correct procedure did not help, but now I know I did it correctly according to Apple.

This also revealed a number of other things in my reading. The only thing not out of kilter is the video. I get a chime, the other lights and LEDs act correctly and nothing else is amiss, just the video.


I used a flashlight to illuminate the screen upon boot and found that the backlight is not coming on. There is a dark, but seeable display on the LCD panel. So I have "tested" the LCD and found the backlight is the issue and the display does work. Now all that needs to be found is why the Logic Board had no trouble in the busted Mid-case and does not trigger the backlight in the not busted, but water damaged Mid-case. I also tried the original LCD assembly with the broken hinge mounting point too and did not get a backlight to come on either. I am speculating here as I did not try the flashlight thing, but that screen was fully display functional just a couple of hours before I swapped the LB to replace the water damaged one. I tried it after I could not get the original screen from the water damaged MBP to work on the swapped LB.


Did you change the DC in board as well? Have you checked the backlight fuse as well as the LED driver?


I used the DC in board from the MC724LL/A as the same board from the MD313LL/A was water damaged. I could see corrosion on it. Interesting you should mention the backlight fuse and LED driver! I gave the MacBook Pro one last reboot mid-evening last night and lo and behold the external monitor started working again! I took that as a positive sign and used my flashlight to install Lion successfully! So the only issue I now seem to have is that backlight which I read a little about and will do more so today. Also interesting that what is on the external monitor is NOT what is on the LCD display. In Windows there is a mirror (duplicate) and extended (additional) modes for a second display. Do I have an extended display on external since it is not the same?


Of course the alternate theory is the backlight on the LCD panel is burned out. So the LCD assembly I purchased is not out of the woods yet as a suspect...


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Get a sata to usb or insert the hdd into another computer and install the os there. For the display, I cant really help you.

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One time, back in the day of the powerbook, my dad bricked his hdd. I used FIREWIRE to install the os because his laptop wouldn't take it. FIREWIRE.


No the hard drive is not the issue. It is very happy in another MD313LL/A performing perfectly. This seems to be a hardware issue on the Logic Board or some hardware connected to it or a setting issue. I just do not know where to go or what to try next. I do appreciate your suggestion though. If we eliminate possibilities that are not the issue eventually we will be left with possibilities that are the cause of the issue...


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fasthans будет вечно благодарен.
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