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Water damaged 820-00239. Replaced U3100 and U2890 along with all resistors and caps in that area and a few jumper wires. Suck at 5v at 0amp on all usb c ports. I do have PP3V3_G3H.
So i actually got it to boot. After testing and comparing diode readings to another board it looks like U3200 wasn't getting PP3V3_G3H but the rest of the board was so after one more jumper wire we have 20v and it boots!!!!!. But its a 2016 so its got flexgate.... time to call the customer and tell them something I'm sure they already know but failed to mention....
Alright so digging into the critical update issue. Ran diode mode on both touch bar connectors and compared to a know good board. found a I had a broken line to pin 20 and 21 on J4402 for the touch bar ran yet another jumper but still getting error. Testing with a known good display and top case and USB OS. SSD can be accessed with lifeboat in place.