820-3437 not detecting internal ssd

[Yoel Ren]

Came in with liquid at smc area, tried reballing smc, now mac boot up fine. But internal ssd not detected, so im sure not an apfs problem.
U3740 has proper voltage 3v at pin 1 3 4 6
1v at pin 2
0 volt at pin 7 and 8 with ssd connected..
I have tried replacing all caps at pcie data line, no shorted caps
0v on pp3v3_s0sw_ssd_flt with ssd connected, I have tried replacing u3710 and u3711.. Any advice?

 

[2informaticos]

"0v on pp3v3_s0sw_ssd_flt with ssd connected"
First check diode mode to ground, w/ and w/o SSD connected.
If all good, change L3700.

 

[Yoel Ren]

Diode mode to ground is normal 0.478 with/without ssd i havr replaced l3700.but still same

 

[2informaticos]

"0v on pp3v3_s0sw_ssd_flt"
Do you get the voltage now???

 

[Yoel Ren]

now there's 3.3 volt but still not seeing ssd

 

[2informaticos]

Clean J3700, inspect PCIE traces and caps.

 

[Yoel Ren]

Cleaned j3700, pcie caps has been replaced, traces is good..

 

[2informaticos]

Did you try another SSD?

 

[Yoel Ren]

Yeah, all ssd used is known good, i have used multiple ssd

 

[2informaticos]

Heat CPU with quality flux; try to burn eventually accumulated crap.
Compare diode mode readings on all PCIE data lines.

 

[Yoel Ren]

Indeed this board is very dusty and not clean, i have heated pch and tried wiring r1620, but still doesnt see ssd, pch fault then? ??

 

[Yoel Ren]

All diode mode is approximately 0.300, except pin 2 of c3710/11/12/13 which is 0v, but i have compared with working board, measured the same so its fine

 

[2informaticos]

There should still be something affected by corrosion.
Else, bad PCH...