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820-00165

I

iMuhtaseb

Member
This board came in for no power; PPBUS was shorted, inject 1V and took off the bad cap, which was C7324.. now PPBUS is clear of short.
But the board is still not powering on; after visual inspection I found out that had corrosion on pin #2 and #3.. I replaced the chip and the board is still refusing to power on..
Although the symptoms are different where I get a fan spin.. then stop.. then a continuous fan spin.. if I unplug and replug.. I get no fan whatsoever..

When then fan spins I get PP1V05_S0.. Any clue on where to look?
 
I

iMuhtaseb

Member
I’ll do that tomorrow. Its weird that its either as simple as just replacing a fuse or an internal failure.

question: can i use just a wire instead of F7140 just for testing purposes?
 
I

iMuhtaseb

Member
Fuse replaced; still behaving the same..
I really cannot rely on voltage readings because when I start probing around.. PPBUS or 3v3_S4 or anything the fan spins..
So I took the diode mode readings of all power rails and it all seems to fit with 1. FlexBV (although my readings were higher in all readings I guess that's for the multimeter differences) and 2. another board that I have.

What was a bit suspicious to PP1V05_S0 so I replaced U8005; same issue
also PP1V05S0_DRVH_R was kinda weird going up then down.. I replaced both U7600 and Q7630; same issue

Dunno what's wrong with this board.. it was supposed to be a clean easy job of PPBUS_G3H; take it off and boom happy A1466...
 
2informaticos

2informaticos

Administrator
Staff member
When the fan starts to spin, do you get CPU core voltage?
Are you using original Magsafe 2 charger?
 
I

iMuhtaseb

Member
No USB Activity, sadly.

The computer is behaving weirdly I'm going to describe it as much as I can:
A normal bare board power on behavior for 820-00165 when you plug in the MagSafe charger should be a take a few seconds to turn on the fan then a continuous fan spin remains.

This board is different; I don't get the fan spin as soon as I plug in the charger.. I might get it 30 seconds after or "randomly" when I probe around areas.. and now (I say now because it's different than it used to) when the fan spins it does for 5 seconds then it shuts off..
 
I

iMuhtaseb

Member
Without the LIO flex cable connected the fan is not spinning at all.. I gave it its time; nothing.. I probed around; nothing.

I started measuring for voltages;
PPBUS = 8.6v
RTC = 3.3v
PP5V_S5 = 5V
PP5v_S4 = not there. diode mode 0.440
PM_SLP_S4_L not there. diode more 0.500
 
2informaticos

2informaticos

Administrator
Staff member
May have accumulated crap underneath CPU.
You can try heating it with quality flux.

I also recommend to reball SMC.
 
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