A2289 820-01987 stuck at 5v, .23a.

[mgladin]

Greetings,

I have a MacBook I am looking at that is stuck at 5v. I just had the same board in with the same issue a couple of weeks ago, so I checked around the CD3217 ICs and found a short on C3208 (PP3V3_UPC_XB_LDO), so I removed the CD3217 IC and found the short was removed. I proceeded to replace the ICs on both sides to be safe, but the issue still persists. I cannot get it to boot into DFU mode either, so not sure what I am either doing wrong or what the issue may actually end up being. Any suggestions to help me proceed forward? Thanks in advance.

Edit: I checked all lines around the IC and found that all the readings were correct.

 

[2informaticos]

Did you get CD3217 chips from same model donor board?
You must also maintain same position in MLB, when solder the chips.

 

[mgladin]

I ordered new ICs.

I also put them on in the same orientation as they came off, but not sure what MLB means.

 

[2informaticos]

Really new (useless), or removed from same board model???

 

[mgladin]

New, not removed from a board or anything. I think I now can assume they may need to be programmed?

 

[2informaticos]

I was thinking you already understood that...

 

[mgladin]

No, I didn't see anything stating they needed to be programmed before use. I used the only exact-match donor board I had when I did my last repair and it seemed to work just fine, so that along with no notation when I ordered led me to believe it was a simple swap. Does the donor board need to be an 820-01987, or can I use any board that matches the chip itself?

 

[2informaticos]

You must get them from same 01987 board model, maintaining their position.

 

[mgladin]

Ok, thanks for the info. I will see what I can figure out. Is there a cheatsheet or something that shows what ICs need programmed if new so I know to pull them off a donor board and I don't run into this again?

Edit: Also, is there a good place to pick up donor boards other than eBay?

 

[2informaticos]

No way to program these chips.
That's the reason to get them from same donor model, maintaining the position in the board.

Recovered chips should be available on Aliexpress.
However, I'm not sure if they really mark them correctly before removing.