Issue Mariko Board

I have a mariko card that doesn’t want to connect. I did several voltage tests and realized that the following component is giving 0v
In the diode test it is normal. But when I connect the card to the charger it does not energize.
Could this be a problem on the max 17050? Or is it something else? What are the right voltages of these components around the max 17050?
issue mariko board

According to my documentation it’s a 100K pullup resistor being pulled high to 1V8PDR which is generated by the main PMIC (MAX77620) and can be measured on one of the inductors surrounding it.

But this rail goes almost everywhere and can also be found here
M92T36 1v8

Attach battery and prompt to boot with cable and measure the voltage at that location, if you measure 1.8V there then disconnect battery/power and test one side of the resistor has continuity to this rail

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Thank you very much for the advice!
Apparently the
MAX77621 below the cpu is defective.
I have a hot air gun, but I don’t know if I can remove this component and insert a new one without damaging other components

Can you give me any tips?

No worries,

Can i ask what makes you say that and what led to this conclusion?

Yeah be patient for now and don’t do anything hasty… it might not be the problem. I’ll give further tips once i know more regarding fault/s :slight_smile:

Did you measure 1.8V at the highlighted spot earlier?

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I tested the continuity of each capacitor and ended up finding a short at the highlighted point. I removed the capacitor and the short remained. If I’m not mistaken this is due to the ic that is failing, correct?

I’ll do it as soon as I get home

Switch your meter over to resistance and measure to ground on those caps you highlited and post the readings in ohms (Ω) so i can verify

Hello, I just made the tests from the image you requested and the results are below.
Note that I did not put the pin value of max77620 because I was unable to place my probe in that location.Sem título

if i did it wrong you can explain it to me again, because i’m using google translator and i don’t have much experience with electronics. Everything I know I learned on my own. Thanks for the help and patience.

Sorry to say, if your multimeter isn’t faulty and your measuring the correct points and you are truly measuring 2.46V or 3.81V on the points marked in red, then the SoC, EMMC and Ram are in all certainty dead.

Your almost correct but just measuring the wrong side of the caps it seems… though as i say unfortunately it won’t matter if your previous voltage measurements are correct .

I’ll make a video to show how I’m measuring, ok. I removed the emmc from the plate to make the previous measurements. I’ll put it in place and redo the measurement.