This board trolled me. The fact that we got fan spin threw me off as I didn't think that would be possible with a partial short to ground on a S4 rail. A couple things to note: *This board was sent from another shop, that messed with the isl circuit. *This board was liquid damaged some time ago, and run through a ultrasonic cleaner, leaving decimated components on the board. *A drop caused this failure to present itself. * No ALL SYS PWRGD or PM PCH PWROK assertion. * Fans went fast as the board was basically braindead and just passing 5v_S0 voltage to the fan. ------------------------------------------------------- **Board View software used in this video, Created by Paul Daniels, is the only board view software available to the repair industry that has PDF integration -- Buy today! - http://pldaniels.com/flexbv/ **Liquid Damaged MacBook? Told it's not fixable or that it needs a new logic board? Don't loose hope yet! -- www.tcrscircuit.repair **Are you another store looking to outsource logic board repairs? Discounted rates available to other businesses. -- https://bit.ly/2vAxI5f **Most IC's and parts seen in our videos are purchased from store.rossmanngroup.com **Flux - Amtech NC-559-V2-TF - https://bit.ly/2IMEYEb **Want to pull SMCs like a pro? -- Here's our recommend hot air station - https://bit.ly/2sg9bR5 **Cheap Iron getting stuck to large ground pads? - https://amzn.to/2sa9JIR **Can't see? Here's the microscope we use and recommend. We highly recommend you go with this scope and not the cheap SE400. - https://ebay.to/2ksBxUz