820-3209 (8.2v on F7040)

patrickribbsaeter

New member
New details. The board is getting warm, but no booting. The board is in S0 state.

Have so far many rails:

SMPS = 19V, 0.198 AMP
1. PPBUG3H = 8.20v
2. PPVRTC = 3.3V
3. PP5V_SO = 5V
4. SYSCLK_CLK32K_RTC = 32.768 MHZ
5. SYSCLK_CLK25M_SB = 25 MHZ
6. CPUIMVP_VR_ON = 3.3V
9. ALL_SYS_PWRGD = 3.3V
10. P1V5S0_PGOOD = 3.3V

Some voltages which should be 1.8v/1.05v has 3.3v. To high. What could cause it?
 
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patrickribbsaeter

New member
New details. The board is getting warm, but no booting. The board is in S0 state.

Have so far many rails:

SMPS = 19V, 0.198 AMP
1. PPBUG3H = 8.20v
2. PPVRTC = 3.3V
3. PP5V_SO = 5V
4. SYSCLK_CLK32K_RTC = 32.768 MHZ
5. SYSCLK_CLK25M_SB = 25 MHZ
6. CPUIMVP_VR_ON = 3.3V
9. ALL_SYS_PWRGD = 3.3V
10. P1V5S0_PGOOD = 3.3V

Some voltages which should be 1.8v/1.05v has 3.3v. To high. What could cause it?
 

2informaticos

Administrator
Staff member
"Some voltages which should be 1.8v/1.05v has 3.3v."
Which ones?
I bet you got confused between signals and power rails.
Did you check USB activity?
Known good BIOS is an option to try.
 

patrickribbsaeter

New member
Cool. i check now direct and post shortly..

Havent checked USB circuit yet. anyhting special to look for on that line?

yes, i meant signals. thx..

Known good BIOS is an option to try. You mean replcing the currrent one?
 

patrickribbsaeter

New member
U7400
I have:
1. CPUIMVP_VR_ON
2. VIN


Missing these output voltage/signals from U7400:
1. PGOOD (CPUIMVP_PGOOD)
2. PGOODG (CPUIMVP_AXG_PGOOD)


CPUIMVP_TON = R7402 = Pin1 8.2v, Pin 2 350mv. Its a 90k resistor and it measure ok.



U2750 (AND GATE )
1. I have ALL_SYS_PWRGD but missing the two above voltages PGOOD.

So could the problem be U7400? I have reflow U7400 still nothing, still 0.125 amp on SMPS.

another question: Which of the nr on the schematic 25-1 and 25 comes first in the correct order?
 

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patrickribbsaeter

New member
JohnB8812 Macbook air only needs 8.0-8.20v from my understanding of PPBUS..?

1. I removed C7910 and I have now on R7911 = 3.3V on both pins. DDRREG_EN and USB_PWR_EN both getting 3.3v.
2. U7300 I get all the input voltages except =DDRVTT_EN
3. =DDRVTT_EN takes me to MEMVTT_EN. (here is it where it becomes cloudy because of all the MOSFETs /transistors). See image!
4. U7300: outputs 1.5v but missing PGOOD because I need DDRVTT_EN. Correct?
4. R2810, pin1=3v3, Pin2= 0v
 

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2informaticos

Administrator
Staff member
VTT appears later, after CPU gets VCORE.

"Macbook air only needs 8.0-8.20v from my understanding"
Wrong assumption!
Board can work with this voltage, but will not charge the battery; maybe not recognized at all.
This issue remains to solve after, or you can do that first.
 

patrickribbsaeter

New member
Ok, so need to get the PPBUS up to 8.6v first...?

So the board need to have the correct voltage for battery in order to power on? Basically both adapter and battery voltage needs to be present?

1. I have intermittent green/yellow light on charger. (1. I changed the i/0 Board and the cable, still intermittent light. 2. I changed the ISL6259 as well) still 8.2v on PPBUS.

2informaticos "Board can work with this voltage, but will not charge the battery; maybe not recognized at all." But I should not need the battery connected to get a fanspin, right?
 
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2informaticos

Administrator
Staff member
Board can work with 8.2V!
But is not the correct voltage, without battery.
Is better to fix this issue first.
It could be SMC issue and you may get not working board for other SMC problems.

Battery is not necesarry to boot.

Post diode mode readings (red probe at ground) and voltage at SCL/SDA lines of battery bus.
 

patrickribbsaeter

New member
Diode mode
R5281 = Pin1: 0.800, Pin2: 1600
R5280 = PIN1: 1600, PIN2: 0.800

I happen to miss the voltage lines:
SMBUS_BATT_SCL (R5281) = 3.4v
SMBUS_BATT_SDA (R5280) = 3.4v
 

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2informaticos

Administrator
Staff member
Pin 1 is common; your measurments are confused.
If you get same reading on pin 2, then post the exact voltage too.
Don't forget to manually choose diode mode, if your DMM is autorange.
 

2informaticos

Administrator
Staff member
Try first to start in SMC bypass.
Also check which voltages try to appear when fan spins.
Trigger SMC_ONOFF_L for test.
 

JohnB8812

New member
Do as 2informaticos suggested. It is possible you have a bad SMC from the donor board. Did you pull it from an 820-3209 board?
 
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