Acer ES1-431 schematic

[dspok]

Please share diagram for following model.
Model:Z8AD
DAZ8ADMB6D0 REV. D

[dspok]

Re: Acer ES1-431 schematic

I found the schematic and found SPI_PWR is ground with 6ohm.
Can't figure out the problem.

Anybody?

[piernov]

Re: Acer ES1-431 schematic

Can you post the schematics? It will help to know exactly what is on SPI_PWR line.

[dspok]

Re: Acer ES1-431 schematic

Attached...

[piernov]

Re: Acer ES1-431 schematic

No boardview and no markings on the board? Will not be an easy one... Can you post high resolution picture of both sides of the board? As much details as possible around the BIOS chip (trying to see where does SPI_PWR come from).

[dspok]

Re: Acer ES1-431 schematic

@piernov
Yes no markings on board. As already said SPI_PWR is leaked to ground and it is vcc for both ec and main bios.

[highpulse]

Re: Acer ES1-431 schematic

is it U20 rom ? if so tell me wich is the voltage found on PIN 121 of SIO KBC if not mistaquen its a IT8987E , if you have voltage on that pin , therefore you should have voltage on U20 as well on pin 7 ,8 and 3.

alltough PU11 releases the +3vpcu , so chek carefully first what it the impendace of the coils of 3.3 and 5 volts to ground , a nice way to find it out without boardview its simples in this case

to see wich coil is the 3.3 volts put your multimeter on diode/continuity mode)
PU11 pin 18 its the 5 volts coil so , with one prob touch pin 18 of pu11 and then chek with the outher prob on wich coil it will make continuity the one that does its the 5 volts coils , ~
pu11 pin 8 its the 3.3 coils , do the same thing above to find wich is the 3,3 coil , once you know , put your multimeter on 200ohm scale , and chek both coils to ground and let us know wich the ohm value you get and post it here for we can follow further

[highpulse]

Re: Acer ES1-431 schematic

reading schematic near ROM it says its a W25Q80BWSSIG so its a regular rom feeded by 3.3volts .
altough if you chek on schematic R475 you will see that there are 2 lines for SPI_PWR one 1.8 on S5 state and the regular 3.3 .. so i guess this 1.8 will not be for this revision since bios is high voltage and now lowvoltage.

[dspok]

Re: Acer ES1-431 schematic

@highpulse
3.3 and 5v is present.
Around 20kohm on both coils.

Lifted SIO, no effect.

[piernov]

Re: Acer ES1-431 schematic

Seems like it is fed by 1.8V since it is the "W" variant, not the "V" one. But @dspok will confirm what he has actually got on the board.
SPI_PWR goes to U20 which is the EC ROM. I assume it is the one just right to the M.2 port.
There should be a 0ohm resistor around it which connects SPI_PWR to the +1.8V_S5 line.

+1.8V_S5 comes from PU9, which is also right to the M.2 port, just above EC ROM.
The top coil is +1.8V_S5. Which resistance to ground do you get there?

[dspok]

Re: Acer ES1-431 schematic

@piernov

Yes it is W variant with 1.8 operating voltage.
And PL7 is 6ohm, PL8 is 2.2ohm to gnd.

Lifted both coils, leakage is not towards PU9.

[piernov]

Re: Acer ES1-431 schematic

Do you get any voltage on PL7 or PL8?
Since I guess they go to the SoC, maybe the low resistance is normal (though it's really low for an S5 rail).

[dspok]

Re: Acer ES1-431 schematic

No sign of life in PL7 or PL8.

[piernov]

Re: Acer ES1-431 schematic

Datasheet to RT5041: https://cdn.badcaps-static.com/pdfs/...b23bcb93db.pdf

You need to check VCC, EN_1P05A and SUSPWRDNACK.

VCC has to be 5V, EN_1P05A above 1V and SUSPWRDNACK below 0.4V for the +1.8V_S5 and +1.05V_S5 to come up.

[dspok]

Re: Acer ES1-431 schematic

Ok checked and found VCC 3.3v, EN_1P05A 2.5v, and SUSPWRDNACK 0v.

[highpulse]

Re: Acer ES1-431 schematic

yes , indeed i failed to see that W variant , so yes , so you must follow the 1.8volts line S5 ,

[piernov]

Re: Acer ES1-431 schematic

VCC pin 11 should be 5V, not 3.3V. If it is, the issue is either with PU9 itself or the output is indeed shorted.
Maybe start by removing PU9 in case it's shorting the feedback of +1.8V_S5.
Otherwise I've got no idea…

[highpulse]

Re: Acer ES1-431 schematic

did you lft the bios and cheked if leg 8 is still with 6 ohm , and if so , dod you try to inject around 1 volts on that trace to see the consumption ? alltough cheking all pu9 , the EN's are coming from EC and some from PCH . so you're in a hard time here , because if you replace EC you need programmer to flash it via keyboard line . or at leastr try reprogram the IT8987 if you have a way of doing it .

but also tell me another thing , if you press ONOFF button on the machines , i conclude she does't turn on , but my question is , once you press the onoff button , if you chek the spi_pwr do you notice any kind of oscilation on voltage or impedance ?
let us know

[dspok]

Re: Acer ES1-431 schematic

VCC pin 11 should be 5V, not 3.3V. If it is, the issue is either with PU9 itself or the output is indeed shorted.
Maybe start by removing PU9 in case it's shorting the feedback of +1.8V_S5.
Otherwise I've got no idea…

Schematic says 3.3v as well, will try removing PU9.

[dspok]

Re: Acer ES1-431 schematic

@highpulse
I have removed MAIN and EC.
Removed SIO.
Still 6ohm.

Injected 1v, consumption 0.07
Power button has 3.3v, after pressing nothing happens. No effect on SPI VCC.