820-00165, Pin 4 of U7501 .118v

SMMRepair

Member
I fucking HATE these 820-00165 boards. They seem to break for no god damn reason, or they're so fragile they just die if you look at them wrong.

I'm working on an 820-00165 that had no liquid, but won't turn on. Measuring around, I get all my s5 voltages, and s5_pwrgd is present at R8141, but my pin 4 (P5VS4RS3_EN_R) of U7501 is .196v. I can't recall what the enable voltage should be here, but I'm pretty sure it should be 3.4v. I changed U7501 and Q7520 together, and there's no change.

I hate this model board, and have no clue where to go next. My other enables are present on U7501, but I believe this missing enable voltage is why I have no power.

Thanks in advance for any help.
 
Last edited:

SMMRepair

Member
Thanks, Aprendiz. You're always a good help:

PM_SLP_S4_L is at 0v, I don't see a pulse. When I measured it the first time, it gave me .198--the same reading as pin 4 of U7501. Now I just re-measured it, and it's at 0v, and now so is pin 4 of U7501.

VRTC is present (3.3v). Voltage at R1300 pin 1: 3.3v, pin 2: 3.16v; R1301 pin 1: 3.3v, pin 2: 3.06v; R1302 pin 1: 3.3v, pin 2: 3.3v; R1303 pin 1: 3.3v, pin 2: 3.3v.
 
Last edited:

dukefawks

Administrator
These boards will power cycle when anything is wrong in the power circuit. I doubt this "just" failed, check for corrosion in the usual spots, SMC, U6100, U1950.
 

SMMRepair

Member
Thanks duke. Yes, I've inspected the board incredibly well. Nothing looks bad at all. Only thing I can find is that pin 4 of U7501 is now 0v. It was .118v the very first time I measured it, then it went up to .198v, now it's a solid and steady 0v. All I've done is replace U7501 and Q7520. I'll probably just ditch this one and move on, it's seeming like a nightmare.
 
Top