820-3115 - U7200 Pin 17 fluctuating.

[gcain]

So power comes in on U7200::16 which is a nice steady 12.62v.
But PP5v_S5 which exits on ::17 is fluctuating.

So my questions is, could Q7840 be the problem causing U7200 to brown out and reset, or should I just replace U7200?

 

[aprendiz]

12.62V is a bit high, should be 12.56V, check sense resistors.......

SMC_PM_G2_EN is also fluctuating???

 

[gcain]

12.62V is a bit high, should be 12.56V, check sense resistors.......

Yes, but I figured many components aren't running. Will check and report back shortly.

SMC_PM_G2_EN is also fluctuating???

Correct. From 0 - 3.5v

It seems PP3v42_G3H is fluctuating too now (at least it is at U7941). Didn't pick up on that yesterday.

 

[gcain]

Actually PP3v42_G3H is stable almost everywhere else. :|

 

[gcain]

I've lost the green light and PPDCIN_G3H is going from 16.75 to 15.86 and back again.

 

[aprendiz]

Is this water damage???? Does it work with a pre charged battery???

 

[gcain]

Doesn't appear to be water damaged and is really clean.

Doesn't work off a battery.

 

[dukefawks]

First get green light back. 3V42 present? SMC_RESET high? If both are OK first suspect is crap under the SMC.

 

[gcain]

SMC_RESET is 0.
PP3v42_G3H is missing not completely now.

Seems to be going backwards quickly.

 

[dukefawks]

Fix 3V42 first, you should be able to do that on your own now.

 

[larossmann]

Please explain whether PP3V42_G3H is missing not completely now means you have PP3V42_G3H or don't.

What voltages do you have at pins 1, 3, 4, 6, and 7 of U5010?