@martinrobertson start off with the easy things. Let us know what exact model your logic board is. It should be a 830-00165 but we just want to make sure. Of course, you do need to perform a visual check of the board first. Check for corrosion, as well as missing or burned looking components. The first thing you need to determine is, if you have power to your backlight. For that, check the voltages on your display connector. With your multimeter set to 50VDC (or close to it depending on your meter), Black to ground, Red to pins 3 or 4 and meter in volt mode, you should get around 30V or higher on a good working system. If you do not have any voltage, check the fuse, as well as the power transistors etc. If the voltage is low but there is power, you need to check your boost circuit. Post some images of your board with your Question. That way we can see what you see Bilder zu einer vorhandenen Frage hinzufügen
Save the images for now since you never know what can happen to this answer, so they may disappear :-) Once we know what your tests tell you, we can probably guide you a bit more in regards to the components etc. Nothing is easy but anything is possible. After all, you are coming to iFixit for some help on this and let;'s see if we can at least narrow it down for you.
War diese Antwort hilfreich?