Shorts on 3.3v bus? I need your help

Hello everyone, I come from Japan.

So, Now I trying to fix my nintendo switch and performing trouble shooting.

I found shorts on 3.3v bus but I can not find root cause.

Shorts area are circled in attached picture.(red circle)

I removed M92T36 & P13USB and ALC5639 but shorts still in exist.

Do you have same experience? If you have same experience or some ideas, could you advise me ?

Best regards.

sorry, I trying to attach picture file but I can not attach the files. An error message is appear “Sorry, you can’t embed media items in a post.” I’m not sure this msg.

I changed the web browser, I could attach the file.

It’s tyically as a result of a failed M92 or P13 IC. remove one and see if the short clears else remove the other

Thank you for your reply.

Yes, I think so too. However, it was not in this case. First, I removed M92 but the short was existed. Second, I removed P13 IC but the short was existed too.

I have already checked M92 and P13 IC.

M92 and P13 IC were removed but the shorts were existed.

Does the short remain with the EMMC module disconnected?

What is the resistance to ground specifically?

Yes I do. I removed EMMC module but the shorts was remaining.

I measured between area where was shorted to ground was 0.5 ohms.

Do you have a bench PSU?

you mean “PSU” is Power Supply Unit which is adjustable?

I don’t have a PSU.

Should I find the shorts point while supplying electric power?

Yeah, if you were to have one I’d disconnect the EMMC module for the time being and then connect your PSU up to your shorted rail and supply no greater than 1.2V (in case it’s shorted elswhere) and with a current limit of 500mA to begin with and then see what if anything gets hot.

This is not always a foolproof method but there is so many things residing on this rail that it’s a bit of a pain and failing the above you have to start pulling things off the board to rule out.

Hi, Severence san, I bought PSU and supplied 1.2V & 0.5A but I don’t feel hot spot.
I don’t have thermal camera. I know if I have a thermal camera, it’s easy to find hot spot.

In this case, Can I increase voltage or Amps?

Do you know other methods to find hot spot?

Best regards.

RAMP UP the amp to 5A and see how much the short draws

Increase the current in 100mA increments until you can feel te culprit getting hot. I would not recommend setting the currrent limit high straight off the bat in case you clear the short before finding the culpit.

Thank you sooo much!

I found shorted capacitor at 1amp. I removed this capacitor and then I confirmed shorts circuit was gone.

Do you know this parts number?

I feel like that this capacitor is same as left one.

best regards.


Thats great news! I’m really glad you were able to find the culprit.

The capacitor is a 22 uF 6.3V

Your’e right it’s the same as the one next to it.

You can find one here

I bought new capacitor and then replaced it. I confirmed that the shorts was gone.
However, Switch start up was failed.
Before I replaced a shorted capacitor, Switch start up was failed with black screen.( no logo, no back lights) After I replaced a shorted capacitor, Switch start up was failed after the Nintendo logo mark.

I monitored the charging voltage and current during start up.

Before turn on the switch, voltage is about 15V and current is about 0.4 amps.
5 seconds After turn on the switch, Voltage and Current are shutdown.( probably 0V and 0amps. I can not confirm it because the USB tester go turned off.)

In this case, failure is still in exist on my Switch?

Best regards.

This i possibly a good sign as it’s indicating your switch is trying to boot. (the drop to 0A)

I would look carefully at the M92 IC and check for any issues in regards to your soldering, It’s also entirely possible the M92 IC has failed at which point it might be worth replacing.

The BQ IC would be the next port of call if thie above does not resolve your issues.

this is the first logo right? you don’t make it to the second logo?

Yes, Switch is shutdown after the first logo.

I’m going to inspection at the M92 IC. Are any issues bridge terminal or poor contact ?

I have already ordered M92 IC from aliexpress.

It’s possible.

Make sure the seller and item have good user feedback, I hear there are fakes floating around, Pickup a BQ IC also while your at it

You could also remove the M92 IC and try booting the console with just the battery and if the M92 was the issue then HOS will startup with an error code.