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.
I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...
I never saw this behavior yet.
Try first revive option; it will preserve SSD information.
If no luck, you may need to try restore; be aware, will erase SSD...
Here are pictures of the damaged areas - after cleaning with flux and heatgun. The filenames tell you the part/area. there are three pictures from u8600 with a hole in the underfill material - is this from the production process or could this be an damage?
Your board has a damage caused by liquid more than sure; not 100% U8600, can be somewhere else.
You can try to heat all BGA chips with quality flux.
In case need to burn accumulated crap underneath.
If problem is U8600 related, that explains why T2 cannot complete DFU.