I have had this problem for nearly a year (here in 2018), but none of the solutions suggested anywhere worked. After tearing my laptop down and rebuilding it numerous times, I finally decided to think for myself. I had noticed that hitting top cover slightly below and to the left of the keyboard often made the problem disappear momentarily - sometimes for a few seconds, sometimes less. I tried the cable idea above, but that didn't work, and it also didn't explain why pushing in this area, nowhere near the monitor cable, would clear up the problem for a moment. What I found was that the adhesive on the motherboard around the four corners of an FPGA chip from Lattice Semiconductors had I guess expanded over the years and pushed the chip up and off the motherboard to where it was not making sufficient contact (photo attacked). I have no idea what this substance is around the chip; I do not believe it was manufactured originally with it, so perhaps it was a repair procedure Apple performed at one of the laptop's visits to repair depots.
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I have had this yellow screen problem for nearly a year on this antique beast that I love, but none of the solutions suggested anywhere worked, including the one here pertaining to the video cable. So, after tearing my laptop down and rebuilding it numerous times without success, I finally decided to take a different direction. I had noticed that hitting top cover slightly below and to the left of the keyboard (near the USB ports) often made the problem disappear momentarily - sometimes for a few seconds, sometimes less. I got curious since this was nowhere near the monitor cable in the display, so I explored the area near the USB ports.
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I also don't understand the role this chip plays in video management, since FPGAs aren't what I would have thought would be in the video processing path. But they're fast enough and general-purpose enough they can be. And speaking just pragmatically, it clearly IS involved, because pushing down hard with my thumb to reseat this one chip immediately and permanently fixed the problem (well, for several days since, a couple of orders of magnitude longer than anything else I've tried).
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What I quickly discovered was an odd sort of silicone caulk, some clear, some black, acting perhaps as an adhesive on the motherboard around the four corners of an FPGA chip from Lattice Semiconductors. It looked like the result of a repair, not original manufacturing, and I had the laptop in to repair several times over the last 7 years. What I found was that the chip had a little "give"; it moved when I pushed it. And by pushing firmly down with my thumb immediately and so far permanently fixed the problem. I'm mystified why this chip would be in the video datapath, not a common role in my experience, but it certainly has the processing power to handle things that fast. But it worked.
So since this is a totally different repair than all others suggested, perhaps it will be what works for at least one more person. The chip in question is square, just in from the edge of the board with the USB ports, between the second and third port I'd say, maybe 30mm (1.5") in from the edge. Photo of the chip attached with the strange silicone caulk-looking material around the four corners.
[image|1493925]
It's located in about the same place as it shown for the 2011 15" MBP shown in step 13 in this ifixit guide: [guide|4990|Teardown 15" MBP]
I have had this problem for nearly a year (here in 2018), but none of the solutions suggested anywhere worked. After tearing my laptop down and rebuilding it numerous times, I finally decided to think for myself. I had noticed that hitting top cover slightly below and to the left of the keyboard often made the problem disappear momentarily - sometimes for a few seconds, sometimes less. I tried the cable idea above, but that didn't work, and it also didn't explain why pushing in this area, nowhere near the monitor cable, would clear up the problem for a moment. What I found was that the adhesive on the motherboard around the four corners of an FPGA chip from Lattice Semiconductors had I guess expanded over the years and pushed the chip up and off the motherboard to where it was not making sufficient contact (photo attacked). I have no idea what this substance is around the chip; I do not believe it was manufactured originally with it, so perhaps it was a repair procedure Apple performed at one of the laptop's visits to repair depots.
I also don't understand the role this chip plays in video management, since FPGAs aren't what I would have thought would be in the video processing path. But they're fast enough and general-purpose enough they can be. And speaking just pragmatically, it clearly IS involved, because pushing down hard with my thumb to reseat this one chip immediately and permanently fixed the problem (well, for several days since, a couple of orders of magnitude longer than anything else I've tried).
So since this is a totally different repair than all others suggested, perhaps it will be what works for at least one more person. The chip in question is square, just in from the edge of the board with the USB ports, between the second and third port I'd say, maybe 30mm (1.5") in from the edge. Photo of the chip attached with the strange silicone caulk-looking material around the four corners.
[image|1493925]
It's located in about the same place as it shown for the 2011 15" MBP shown in step 13 in this ifixit guide: [guide|4990|Teardown 15" MBP]
Cheers, kevin