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MacBook A2141 820-01700

I

iFix

Member
Hi, I have this 820-01700 board which came with no power. After inspection, I saw that the SSD line is shorted on PP2V5_NAND_SSD0, PP1V8_SSD0, and PP0V9_SSD0. Also, U9580 had to be replaced because it was shorting PPBUS_G3H. I replaced U9580 and U9500 to be sure all is good and found that ALL SSD chips from the left side are dead all burned on one of the lines mentioned above. Now there are no electronic issues, but I cannot get it to enter DFU mode, so I was wondering if anyone has experience if it's possible to boot DFU mode only with one side SSD chips. It boosts to 20v goes up to 0.4amps then 0.6, 0.7 and goes back down and again in a loop to 0amps.

Ideas would be appreciated :) Thanks
 
2informaticos

2informaticos

Administrator
Staff member
How many NANDs had the board in original configuration?
In case of 5, you can use it with just 4 on one side; once replaced with good ones.
 
I

iFix

Member
This board is with 6 NANDs, of which 4 from the left side are dead, the 2 on the right side and the circuit is fine. I tried to force it to DFU mode and restore but it didn't want, it showed and error. Now if got 4 other NANDs from another board and I will try them and again DFU hope it will be good, if not i guess i have to chance them all ?
 
I

iFix

Member
2 on the right side are fine I meant and the circuit on both sides :) I tried to restore with 3 other NANDs on the left side but shows the same eror as before only with the 2 nands from the right side --- Gave up waiting for device to transition from DFU state to DFU State---
 
2informaticos

2informaticos

Administrator
Staff member
You may need to replace all chips.
Be sure to solder them in the correct location.

Now depends the original size of SSD.
Bigger SSD requires customized T2.
 
I

iFix

Member
The ''new'' nands are from an older model but the same and I don't think they are more than 500GB all of them the old and new. What would be the correct location you mean left and right ? I resoldered the new nands on the place where the old were
 
2informaticos

2informaticos

Administrator
Staff member
Each chip has a marking code; confirm the capacity.
With correct place I mean the same position in schematic; U8600 must be replaced with chip removed from U8600 place, etc.
You can also buy pre-marked NANDs kit from Aliexpress.
 
Last edited:
I

iFix

Member
I already soldered them, but not in order now i wouldn't know where they need to go. Can they be from another model and how many they need to be?
 
2informaticos

2informaticos

Administrator
Staff member
Can be from other model, just need to check size compatibility.
You can downgrade from 512GB to 256GB, for example.
 
I

iFix

Member
okey then i have an A1990 just have to confirm the size. Do I need to remove the last 2 from right side chips to install the new ones?
 
I

iFix

Member
I removed the 2 left from the original SSD chips and I tried to restore and/or revive it just with the 4 new chips, which are probably in the wrong position and still I get the msg ''Gave up waiting for device to transition from DFU state to DFU State'' - 0xFCA(4042)
 
2informaticos

2informaticos

Administrator
Staff member
Can't fix, if the chips are not in correct positions.
Also, should remove power chips for the side where you've ripped off the two NANDs.
 
I

iFix

Member
Hello. Does it make a difference that I have also replaced U9500. I will try without U9000 and U9080 from the other side maybe it will boot up DFU mode...
 
I

iFix

Member
Hi. Something that I didn't mention is that the new ships are black, not silver like the original...
 
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