Chosen Solution
Hello, My MBP 15” Mid 2010 with NVIDIA GT330M doesn’t recognize anymore my U2713hm screen plugged by displayport. (clamshell mode) If I connect it with a displayport cable it either doesn’t recognize it and in the console it reports: WindowServer (Core Display) [ERROR] - Unknown CGXDisplayDevice: 0x41dc9d00 Or now when it works randomly it’s detected as a generic screen and only outputs 1080p instead of the 2560px resolution. Connected with displayport to DVI it doesn’t work too, it only works in hdmi limited to 1080p (screen’s HDMI limit) I tried the following: new cables, 2 different displayport cables DDC/CI mode disabled on the screen Factory reset of the screen a couple of PRAM and SMC reset 10.13.6 clean install removal of com.apple.windowserver.plist Nothing works. When this started I replaced the capacitor that is known to fail on this Mac but it didn’t change anything. The motherboard was replaced by Apple, it looks like it was a refurbished one and the capacitor I replaced looked like it was already replaced as there was green paint dots added on it, the new one is the one advised on forums. Also the computer had the thermal paste replaced. There is no kernel panics, no visible problems, only the external screen not recognized. Is there anything I could do to fix this? Thank you.
Sadly, the onboard diagnostics won’t test the miniDP port logic. Either the connector has become worn so it’s not mating one or more contacts or the decode logic which identifies the display has failed. The fact its sporadic may also be a cold solder joint on the connector and/or along the trace lines from it and the components connected or just a failing component. Someone with good micro soldering skills might be able to save the logic board otherwise its time for a new logic board - Sorry
