820-00928 A1707 MacBook Pro 2017 with NAND damage

[sekidata]

I have a 820-00928 board that has physical damage to two NAND chips and needs replacements from a donor board. This is a T1 machine; do I need to replace all 4 NAND chips or can I just transplant the 2 damaged ones?

 

[2informaticos]

Replace the burnt chips and test.
It should work...

 

[sekidata]

Also, would you recommend cleaning up all the black underfill from the board, or just placing the reballed chips on top of it, trusting that the balls will make contact? See photo.

 

[2informaticos]

Clean that; be sure to get good solders.
Many videos available on Internet, about changing NANDs...