I have reset mine with guide with https://integer13.wordpress.com/2018/04/...-31mu97-not-powering-on-how-to-repair-this-piece-of-sht/ for awhile then all went back again after power out in my home area. :( now trick with Amp meter does not work :(. I have purchased replacement IC205 ROM from ebay but I do not have tools to do the board repair :( My question is What do I need to do the replacement IC succesfully? what tools do I need?

HI,

I have same problem, power on magsafe but no display usb power. I solved my problem by replacing logic board.

good luck.

I am tying to fix mine with no screen, no usb but there is power to my macpro via magsafe.

I have replaced power board but same NO SCREEN.

Does anyone know how to test the 27” screen it self? I dont have fancy LCD screen tester