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820-3023 no boot/fan spins

S

sangolossyfon

Member
Board slowly spins fan to max, draws 6w.
SMC bypass still draws 6w but fan spins up faster.

ALL S5, S3, S0 on 5V and 3v3 are correct voltage (5.91, 3.85) as are G3H(9.5v) and 3V42.
PP1V05_S0 and PP1V5_S3RS0 are 1.2 and 1.73v respectively. PPVCCSA_S0_CPU is 1.04v, but both PPVCORE_S0_CPU and the AXG rail are 0v. Even in SMC bypass mode.
However no shorts on these two 0v rails. 12.5 ohms to ground.
Thoughts? This board was working previously and booting to question mark, I don't know what happened to it.
 
2informaticos

2informaticos

Administrator
Staff member
First, I recommend to change the battery of your multimeter.
Actually you get higher indications than expected.

Check if ALL_SYS_PWRGD goes high.
 
S

sangolossyfon

Member
board is working! I can tell it is posting because of power draw and fan being normal. But this board did have another issue which was the initial reason I started working on it.

Board works when both charger and battery plugged in. When I unplug the charger, the board stays on, running off battery power.

However, after it is turned off, it will not turn on when just the battery is connected. It requires the charger being in to turn off and on.

I also don't believe the battery is charging as it draws no power while off.

the power button works because I can use it to turn off the board.

I did realize that I had shorted SMBUS_SMC_5_G3_SCL to PPVBAT_G3H_CONN in the process of fixing the battery connector, and this short had been active while the board was on, so this line undoubtedly got the full battery voltage pumped through it... :( i have since removed this short, but the board had the same behavior while the short was active.
 
S

sangolossyfon

Member
I did replace it and it does the same thing. SMC is beyond my skill at the moment so I am going to just use this board as a desktop mac/always plugged in. but thank you for the help.
 
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