Adding onto @danj ‘s solution, this appears to be a Logic Board problem because as Dan said you are getting voltage to the Logic Board. You can buy a new Logic Board at the link below. There isn’t a specific guide on how to replace the Logic Board, but you can follow the guide I have included below also. Just disconnect any other cables that need to be disconnected at step 19 and you should be golden.
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Adding onto @danj ‘s solution (respectively mark his answer as correct if you do decide to mark an answer as correct), this appears to be a Logic Board problem because as Dan said you are getting voltage to the Logic Board. You can buy a new Logic Board at the link below. There isn’t a specific guide on how to replace the Logic Board, but you can follow the guide I have included below also. Just disconnect any other cables that need to be disconnected at step 19 and you should be golden.
Adding onto @danj ‘s solution, this appears to be a Logic Board problem because as Dan said you are getting voltage to the Logic Board. You can buy a new Logic Board at the link below. You can follow the guide I have included below also, just disconnect any other cables that need to be disconnected at step 19 and you should be golden.
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Adding onto @danj ‘s solution, this appears to be a Logic Board problem because as Dan said you are getting voltage to the Logic Board. You can buy a new Logic Board at the link below. There isn’t a specific guide on how to replace the Logic Board, but you can follow the guide I have included below also. Just disconnect any other cables that need to be disconnected at step 19 and you should be golden.
Adding onto @danj ‘s solution, this appears to be a Logic Board problem because as Dan said you are getting voltage to the Logic Board. You can buy a new Logic Board at the link below. You can follow the guide I have included below also, just disconnect any other cables that need to be disconnected at step 19 and you should be golden.
[guide|112355]
https://www.macpalace.com/661-6060-logic-board-thunderbolt-display-27-820-2997-639-1575-a1407.html