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Keep in mind, x1-3 means x1, x2 and x3; x1/2 means x1 and x2.
Just in case, x/y1/2 means x1, x2, y1 and y2; example R/C7030/40 (look at 00840 board).
We use many times such kind of short names in the forum.
Try changing U8400.
Any history available?
BKLT_SD stays low?