A2141 820-01700 PP2V5_NAND_SSD1 shorted

[hgoncalves]

Hi,

I have an A2141 820-01700 that has 19V on ampmeter, but only 0.06A.

PP2V5_NAND_SSD1 is shorted and CC929 was burnt, and a test pad is gone.

I supose that at least one nand will be burnt. Am I correct? How can I be sure? Can I inject 1V there?

TKS

 

[2informaticos]

You can inject voltage...

 

[hgoncalves]

Hi,

C8648 was shorted. After replacing it, now I have 2.5V on PP2V5_NAND_SSD1.

Mac takes 19.8V on ampmeter, but 0A (goes to 0.15A but drops to 0A). Should I try DFU restore?

 

[2informaticos]

Go for restore, if no data to save.

 

[hgoncalves]

DFU restore failed with an error. Any other idea?

It seams that it is rebooting. Fully assembled, It reatches 0.78A and goes to 0A continuasly. Everythind disconected it stays at 0A.

 

[2informaticos]

Be sure to start from DFU, not Recovery mode.
Use 96/140W charger and connect battery too.

 

[hgoncalves]

Hi,

I'm in DFU mode, and I'm using an original 96W charger, and still have the same error.

 

[2informaticos]

Possibly damaged NAND chips...

 

[hgoncalves]

Now it stoped being recognized in DFU. It still has 2.5V on PP2V5_NAND_SSD1, but no power on

20V and 0A on ampmeter

 

[hgoncalves]

Now it is rebooting. Measuring the power lines, I notice that it reboots (goes to 0V and them up again)

Following the power sequence page, I notice that:

P1V1_SLPDDR_SOCFET_EN has 1.8V (I think it should have 1.1V)

Any idea?

 

[2informaticos]

Pay more atention when you read a schematic.
Enable signal, is not an output voltage.

Did you try to force it in DFU mode?

 

[hgoncalves]

Yes. I did try it a few times.

 

[hgoncalves]

Forcing DFU might have damage the NAND (or something else)?

 

[2informaticos]

If you didn't put more than 1.8V into SOC_FORCE_DFU (by error), no problem for SSD, or T2.

 

[hgoncalves]

Hi. No I haven't done anything like that. Just tried a few times (4 or 5) the DFU restore.

Is there somthing else that i can try?

 

[hgoncalves]

Hi,

I've PP3V3_S5 and PP1V8_S5 missing.

PP3V3_S5 = 0V and 0.350 on diode reading
PP1V8_S5 = 0V and 0.334 on diode reading

Can you help?

 

[2informaticos]

If you can't enter DFU, may have problems with T2.