820-02917 (A2991): Powers up on battery but not USB-C

repMacFixit

New member
Can't located a brdview, so working somewhat in the dark. I have the board that powers up on battery but not via any of the usb-c ports. Left port by MagSafe pulls 5v @0.11A, then next beside that 20v 0A, and at HDMI side, 5v 0.32A. With battery pulled, they are all 5v with the one by the MagSafe still only pulling 0.11A and all the others (except for the MagSafe) are fluctuating between 0.06A and 0.32A. Using a IR camera, usb-c chip (UF400 on A2148) get up to about 110 degrees when power is applied to either of the two ports on the MagSafe side. I'm looking to replacing that chip which is a SN24A12 but all i can find is a SN25A12. So research into this and i'm finding these chips are interchangeable, is this correct?
 

2informaticos

Administrator
Staff member
You can replace only damaged SN25A chip; but must replace its corresponding ROM chip also.
In other words, you must take out mentioned chips from same model board, maintaining their position.
 
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