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820-01958 water damage, now no boot!

M

Maxibon

Member
I have a Macbook pro in - 820 - 01958 that had water damage around U7650

I'm getting 20v at .07amp with my amp meter


After checking on the forum I've found some info on putting these info DFU etc, though I don't have another machine to test this unfortunately.

I've found one of the R32 coils that I'm getting 0.000 on both sides with diode mode

To confirm, this means the CPU is shorted in most cases right?


I would usually already be confident with my result, though without having correct schematic and board view I thought I would ask. hoping you guys say I'm jumping the gun.

Thanks.
 
2informaticos

2informaticos

Administrator
Staff member
The CPU core coils show very low values as normal.
You should compare with good similar board; using same generation CPU.
BTW, switch to ohm mode, instead of diode, when you check very low values.

Post basic voltages for U7650; pins 23, 12, 13, 22, 29, 21.
 
M

Maxibon

Member
Thanks a bunch for the insight and tip! I'll make sure I do that in the future,

Unfortunately I don't have another known good board here for this one!

Post basic voltages for U7650; pins 23, 12, 13, 22, 29, 21.

23 = 12.3v
12 = 0v
13 = 0v
22 = 3.3v
29 = 0.3v
21 =0.1v

Thanks for your help as always
 
M

Maxibon

Member
Thanks for your reply.

I'm unsure how I can check these when we don't have access to the correct boardview file... U7650 is similar to other models, though this area isn't :/
 
M

Maxibon

Member
Thanks, sorry don't mean to waste your time, I had a look before posting just not on here.


LDO_CORE = 1.5v
PMU_LDO3_OUT = 1.8v
LDO_RTC = 1.5v

Thanks again!
 
2informaticos

2informaticos

Administrator
Staff member
You've forgot 3 important LDO rails.
Look inside U7800 notations.

Should be good to check all AWAKE and SLPS2R voltages from the board too.
 
M

Maxibon

Member
I understand sorry,

PP0V8_SLPS2R = 0.8v
PP1V8_SLPS2R = 1.8v
PP3V_G3H = 3.0v
PP1V2_AWAKE = 1.2v
PP3V3_G3H = 3.2v
PP3V3_AWAKE = 3.2v
PP3V3_S5 = 0.0v
PMU_VPUMP = 5v
PP1V1_SLPS2R = 1.1v
PP1V1_SLPDDR= 1.1v
P1V1SLPDDR_RAMP = 3.0v
P1V1_SLPDDR_SOCFET_EN = 1.8v

Checked all voltages on page 63 incase that I needed those as well.

Thanks again.
 
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