For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Nothing on screen or HDMI through usb-c, trackpad is clickable
Cpu gets hot but coils L7410/20/30 are all at 0v all other coils are measuring what they should be
Board has minor signs of liquid arround Q8400 area but no corrosion anywhere to be seen
An USB mouse get light?
Better to check with an USB OSX pendrive, with Link LED; if flashes, that confirm 100% USB activity.
Disconnect internall SSD for this test.