Switching the inverter on without the logic board
So my 27” i7 iMac has the famous GPU issue, and I wasn’t one of the lucky ones who had their boards replaced by Apple. After a long period of feeling disgruntled, I finally came to terms with it and successfully turned it into an external display for my MacBook Pro via a 3rd party LCD driver board.
It works great except the supplied inverter is not powerful enough so the backlight is only about half as bright as it was with the original inverter, as explained by the board supplier.
That got my thinking though. I’m using the original PSU board to supply 12V to the new board and inverter via the ‘always on 12V’ rail. And the original inverter is still installed and connected. Potentially all i’d need to do is reconnect the original inverter to the display and supply an ‘on’ signal to it somehow from the new board. The board supplier said there are a couple of places I can get a +5V on source from the new driver board, if that is indeed what is required.
Does anyone know what the PSU and inverter need signal wise (usually from logic board) to switch on? High? Low? What voltage and on what pin(s) ?