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I found Q8012 missing from the board, so will replace that and hope that fixes it, will report back

Customer came back with this Mac so im back on it. Resistors have correct values and traces seem to be OK. I have only 0.6v on pin 5 of U5560, should be 3.3v correct? Thats also what i measure on SMC_1V35MRM_ISENSE. I do have 3.3v at J4800 so it is being created. No short on pin 5 of U5560 as...

Hi, I have a liquid damaged 820-01041 (macbook pro 15 inch touchbar 2018), board looks pretty clean. Doesnt turn on, but is taking a charge 20v and 2.x A. I have no schematics for this board. What other board comes close that is available?

OK got it, its U2750 and that signal comes from U7960, will check. R7974 is OK U2750 Pin 1: 0.086v Pin 2: 0.025v Pin 4: 0v Pin 5: 3.3v R2750 = ok At Q7950 I measure as follows: Pin 1 = 0.7v Pin 3 = 0.086 Pin 4 same Pin 7 = 0.75v Pin 6 = 3.25v Pin 5 = 0.48v All resistors around it measure OK...

Sorry its Q7950. And I cannot find U1950 in schematic, i read they are numbered different for 3209? My board is 820-3209-A

Hello, I have an 820-3209 that was working and suddenly stopped (its our mac). Got green and orange light. After inspection saw some corrosion near U7600, replaced C7601, R7641, R7642 and R2801. Now i got all voltages upto 0.9v, including 1.05v on L7630. Whats missing is power on L7550...

Update: found the short lead to PP5V_S4, replaced C7600 where smoke was coming out, short is gone. I still have a pulse on lines, checked at SMC_PM_G2_EN and also pulsing. U1900 has 32mhz.

ok, found a short on PP5V_S3, diving into the rabit hole :), not too many IC in this circuit though....!

CPU VCore = no pulse 3V42 = Steady Checking for shorts now Could you remind me how to do SMC bypass please? I google it first (ofcourse...) but only find SMC reset and forgot!

Hi Guys, I have an 820-3437 where all the power rails pulls, even PPBUS goes to 8.13 and back to 8.59. I do have green and orange line. Looks like it tries to start, but not. At U7501 I also have pulses on 5v_S5, S4 and 3.3V lines.Board looks pretty clean.

Fixed, this is exactly why i love to pay for the forum, couldnt have figured this without you guys!!!! Learned something again, makes me wonder how many boards i disposed because I thought the CPU was shorted :rolleyes:

I traced it back to U8030, looks like some microscopic corrosion around the IC, will replace it and report back

Hi John L7310 and L7320 have 0V, no signs of hard drops. At U7200 pin 1 CPU_VR_EN i get 0.78v At pin 7 from U1950 I get 2.5-2.6v swinging so seems not OK I measure 2v on PP3V3_S0 which is not good, no short to ground though, i measure 0.522v

Hi Folks, have a 820-4924 that came in today. The board is superclean no liquid. All voltages are there, also 5V_S0. The CPU has 1.05v, but what is missing is 1.8v PPVCC_S0_CPU_REG. I checked U7200, it has on pin 18 0.73v, and on pin 20 and 22 1.96v not sure if that is what it should be? VIN and...

Hi guys, I have an 820-3662 that does not turn on when we connect the 85watt original charger. We do have a green and orange light and PPBUS and 3.42 measure OK. If we connect the battery and then plugin the charger, it works. Cannot find a short in the power circuit, kinda weird, any idea?

I have had 3 units 820-3662 with this issue, all fixed after replacing FDMF IC's.

OK never mind guys, short capacitor C7032:o

Hi guys, I have an 820-3332 with no light on the magsafe. Some small corrosion around Q6896. I check PPBUS as well as PP3V42_G3H and they both have 0v, no shorts. If I check on F6905 i get 0.470v. Tried another Magsafe, and another charger but same. I know how to troubleshoot onewire, but that...

Yes and yes i tried PRAM/SMC reset.

Unfortunately I didnt have enough time, so this one can be closed :(