820-01700 water damage dead 20v 0.05a

yair37

Member
hello 820-01700 after water damage near U9500 and U7220 i was clean and reball this 2.
now at the charger its give 20v but 0.05a without battery.
i notice that pp3v3_g3h_ssd is short on c9504 and c9501 i was take them both and take out also U9500 the dido mode at c9504 was 100 but after few second it show 350.
i was put back the U9500 and measure again pp3v3_g3h_ssd is still 350. i didn't put back c9504 and c9501 and connect the charger again.. on charger 20v and 1.5-2a for few second and drop down to 0.5a and the pp3v3_g3h_ssd again on diode mode 70-100ohm.
ppbus - 12.5
pp3v3_s5 -0v
pp1v8_s5 -0v
 

2informaticos

Administrator
Staff member
Allow 10-15s after power removed, to check diode mode.

3V3_S5 appears at least in the first few seconds?
 

yair37

Member
There is anyway to check or its for sure that the CPU is dead?
Any other way to check? Can U9500 make this problem? If i will replace it its can help?
 

yair37

Member
The wierd thing is When i reball the U9500(nit always) it give me the right V (20)and A(2) at the charger but when i disconnect and reconnect its gone again. V(20) A(0.05)
 

2informaticos

Administrator
Staff member
This not an exact science.
We do not have the (automatic) tools used by Apple in the fabrication line.
But liquid sign in CPU power supply is really bad.
 

2informaticos

Administrator
Staff member
We have several threads about DFU mode; just search the forum.
Too many T2 mahines get T2 corrupted and require DFU restore.

Even if previous post is so short, I don't see any reason to quote it...
 

yair37

Member
UPDATE:
i was try DFU and RESTORE mode and i get error 35 and 4017, i dont find any info about this error.
right side charger with battery and without 5v 0.05a
left side charger with battery 19v 1.5a without 19v 0.a
 

2informaticos

Administrator
Staff member
Then you still have a problem on right side USB-C area.
Compare diode mode readings on basic points with left side.
 

yair37

Member
sorry it was the type -c adapter problem(CHINESE :mad:)...both side with battery 20.2V 1.5A without battery its 20V 0.05A.
 

yair37

Member
Try again DFU with the good charger.
dont work, the mac turn on directly to RCOVERY mode, but i can access to DFU mode, and i get this errors every time.
DFU MODE: step 4 to 4 installing system- load very fast to the end the error 35.
RESTORE MODE: step 4 to 4 installing system - error 4017 at the beginning .
 

yair37

Member
U9500 (ssd) can caused the problem? there was there water damage... and i didnt put back C9504 AND C9501 now o put them back i sew that they CRITICAL but when i put them the PP3V3_G3H_SSD0_SNS show 3.3V and at the restore its stuck at "installation system"
how can i know if U9500 is o.k or not? i dont find this IC to order new one.
 

2informaticos

Administrator
Staff member
You've mentioned liquid sign at U7220 too, in the first post.

Do you get correct voltage at all coils associated with U9500?
We don't really know if T2 needs to talk with CPU to fix the NAND.
 
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