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A2141 - 820-02037-A - liquid - 20V 0,4 Amp. No short to SSD

S

samstown

Member
ok, I got the right way to access DFU with the switch. It's working on both motherboard (Bad and good).

1. Connect only power USB-C on DFU Mother board
2. Open AC2
3. Press the switch and hold it
4. connect thunderbolt USB-C to USB-C to AC2 Intel Macbook
5. DFU should appear

Now I'll try a revive on the bad one.
 
S

samstown

Member
Now that I did try "revive" it take max 0,1 amp, it's no longer going up to 0.4amp

I am not too sure which SSD voltage I need to check

HS_P3V3_G3W_SSD0_OUT = 0.06V
HS_PBUS_MAIN_SSD0 = 0.22 V
P1V8_LX0_SSD0 = 0V


HS_P3V3_G3W_SSD1_OUT = 0.06V
HS_PBUS_MAIN_SSD1 = 0.22 V
P1V8_LX0_SSD0 = 0V
 
2informaticos

2informaticos

Administrator
Staff member
I suppose you are using 01700 schematic, as 02037 isn't available.
SSD0/1 voltages are available on pages 92 & 87.
 
2informaticos

2informaticos

Administrator
Staff member
One bad NAND can cause such fluctuation.

Checked these too?
Some coils may be on the opposite side also.
 

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S

samstown

Member
thanks. 0V on the one you highligthed. I don't have an exact same board to compare. I have a 820-01700 working.
 

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S

samstown

Member
I can put it on DFU only when connected to left side. When I try from right USB-C it doesn't work. I guess it's normal. Revive keep giving same error
 
2informaticos

2informaticos

Administrator
Staff member
There is a dedicated DFU port (only one), left back.

Your problem may be SSD itself; usual for sudden death.
Restore will fail too, in such case.
And data can't be recovered...
 
S

samstown

Member
looking with thermal camera I see heartbeat on TPS51980B (U7650). is the chip faulty or something making the hearbeat happening ?
I've checked all components around and couldn't find anyhting wrong. I'll keep searching.
 

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samstown

Member
yes, L7600 0,5v to 2V (diode mode .032) and L7660 1V to 3,3 V (diode mode .330)
L7211 and L7221 = .006 that's not good, isn't it ?
 
2informaticos

2informaticos

Administrator
Staff member
"L7211 and L7221 = .006"
Looks good for CPU power core rail.

"L7600 0,5v to 2V (diode mode .032)"
This doesn't look good; 0.032 is too low there...
 
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