Switch lite 5V 0.6A

I have nintendo switch lite. Dead. When I bought it, I spotted water damage on the board but nothing major. USB-C was also damaged but although some pins were smashed It still charged at 5V 0.6A. After replacing USB-C it still do the same thing 5V 0.6A. I checked battery and it has around 3.2 to 3.4v and after plugging the cable it is charging the battery cause voltage is going up.
When plugged to the charger and the battery on thermal camera I can se that only thing that is getting warm is BQ chip but I assumed it should get hot because from what I know it is power management chip.

I tried testing capacitors in diode mode around pretty much every chip and although I don’t know what voltage drop they should have, none of them showed a short on both sides. Only on one side but I think that is how it should be.

The only weird thing that I cant explain is that 0Ohm resistor I think next to 17050 BGA chip shows 0.001 voltage drop when measuring diode mode witch red probe on ground an I dont know if it should be this way.

Any ideas are welcome!

If that label 050 on it, that’s the current sense resistor to ground. It’s normal having reading short to ground on it.

For some reason I cant even find a video with problem similar to this one :confused:

Your symptoms are pretty much the most common seen on Switch and there is oodles of info in video form or on the forum. I think perhaps part of the trouble is, your USB ammeter is showing 0.6A instead of the more typical 0.4 or 0.5A . The difference here is just down to the ammeter hardware.So, basically your Switch is in a braindead 0.4A state (which can be a variety of things)

Anyway, given your USB issues, you’d replace M92 IC just as a matter of course, then you’d check all USB related circuitry etc. Tell us where the minor liquid damage was, stop using diode mode, stop randomly measuring things, measure primary rails resistance to ground etc etc :slight_smile:

Good luck :+1:

Thank you very much for your reply. As I think about it right now I should state that I am a newbie to this whole thing.

So the water damage was on this separate board that has connection to power button and left joystick but also I found green corrosion on the game card reader. I didn’t find any signs of liquid damage on the main board and the indicator wasn’t touched by water.

Based on YT the main board should work on its own so I disconnected everything from the main board except the battery and plugged the power only to see that it is stuck at those 5v. After that my assumption was that despite no visible water damage the main board is also faulty.

I’ll try to replace this M92 if I find some free time and I’ll post if it helped but as you mentioned I might also look for another charger because right now I use cheap chinese 8 in 1 20W charger.

As a side question can you explain why I shouldn’t use diode mode when looking for a short to ground? I am asking because I have no knowledge other than those videos I’ve watched on YT. And they used diode mode so I did the same :stuck_out_tongue:

Because 1: diode mode can give very misleading results, in diode mode you can get a “good” reading even when the rail / line in question has issues (soft shorts in particular) 2: Many meter have vastly different voltage / current limits in their respective diode modes, which again can significantly skew results 3: most of the time the people who are using or “demonstrating” diode mode measurments they are doing so reverse polarity, question to yourself, does the circuit ordinarily operate reverse polarity? no, so testing as such may lead to odd scenarios, particularly if there is an issue downstream 4: diode mode on most meters often inherently offers a “low resolution” readout 5: low resistance to ground / low impedence rails / lines cannot reliably be measured using diode mode and you basically have to use resistance mode to get a meaningful measurment which ties back to several of the prior points. 6: diode mode is not as consistent across meter brands as resistance is, which again ties back to some of the other points, so basically, you might get 0.2 and the other guy might get 0.4 (for example)

Diode mode was popularised by people who back in the day had meters which had very “slow” resistance mode measurments and/or they didn’t understand how to use the manual mode on their meter (diode mode is simpler to use) … neither of the cases are an issue in todays day and age. A decent meter will be autoranging on the resistance mode and the speed is basically on par with the diode mode… I mean there are exceptions, for example a lot of the modern fluke meters are based on 20+ year old models / designs so they could still exhibit these problems (a bad meter, they are not really intended for our line of work)

Anyway, hopefully that answers your question in that regard :slight_smile:

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Ok, I replaced M92 for a new one. I had couple attempts but finally I made all the pins connected. But to my surprise after plugging the power it once again showed 5v 0.49a (this time I tried the same all in one charger and it showed 0.6 but I used second one in series with the first one and second showed 0.49 just as you said).

What are the odds that this new m92 is also faulty in the same way?

Battery is charging I checked it and Volts are going up just as before.

Im also thinking about replacing usb-c because although it doesn’t have any bend pins it doesn’t look good and I’m not sure if it is soldered properly with those hidden pins. Is it possible that switch is not turning on on battery because of pins not being connected?

Given your getting 0.5/0.6A after the swap it’s less likely (though there is a lot of fakes on the market) - The Switch would ordinarily boot even without thi IC installed (albeit with an error)

If the concern is open lines (as opposed to bent pins) then this wouldn’t stop the Switch from booting either.

Trouble here is, this “0.4A braindead” state (which you’ll find all over the forum) could be a variety of different things unfortunately and there is no one step solution, I’ve seen fuel gauge cause it, Ram, SoC, bad M92, bad BQ, open resistors, rail shorts cause it, list goes on… So there is no one direction I can send you :frowning: visual inspection usually knocks down some of these steps, then rail checks can knock some of the steps down again, then failing all that it’s the guessing game.

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Ok I’m back with another question because I’ve read some comment about this fuel gauge. This is this 17050 chip on the other side of battery connector right? So when replacing usb-c port I “displaced” it so I took it off, cleaned the pads and I know that this is BGA chip but I didn’t have solder balls at hand so I just re applied solder with my iron and tried to solder it back. It was aligned pretty nice and when I tapped it from the side it slid back into place so I was happy with the result.
But I couldn’t find any information how to test if it is good or not. I tested caps around it in resistance mode and it shows M and k Ohms so no short there.

but the battery charges fine what adds to the confusion if it is good or bad


Ouch, you must have got the board up to some screaming temps for this IC to get displaced all the way back there :open_mouth:

Nope, no good :frowning: . You have a 10% chance of this method ever working (your odds are slightly increased due to the IC’s small size… but still) you have a 90% chance of this not working, then of that 90%, half of that poses the risk (coin toss) of you actually bridging something which shouldn’t be bridged and potentially causing damage.

To hopefully get you back to square one here, grab some of these IC’s on Mouser, wick the pads on the board, and reinstall (chips are preballed) :+1:

Typically, if the IC fails of natural causes or physical damage, then measurments on the surrounding components rarely reveal anything (of course there are exceptions) given how cheap these IC’s are, in your case you’d swap it out. Ordinarily, you’d be looking for chips, nicks and cracks on the body of the IC package.

I’d search recent posts on the forum regarding checking your primary rails (recent picofly / hwfly modchip topics go into this) and provide your measurments here in a image overlay… maybe something will stand out (there is also various other topics where I cover this. I’m not going to find this info for you, this is a trial by fire so to speak so you can actually learn something :stuck_out_tongue: does you no good if I just spoon feed you info as you won’t absorb the info)

I’d also start taking a very close look at the backlight IC and associated components, connector etc as issues here (paritularly in liquid cases) can cause issues. Also, feel free to take pictures of the board in these areas and also the board as a whole front and back (good lighting, good quality, will do me know good If the image is blurry or has shadows etc, I need to be able to see almost as well as you would in the best scenario), who knows, I may be able to spot somethings :slight_smile:

yeah, but not high current charging, so it’s not really telling you anything. Using USB current to diagnose issues is not particularly helpful unfortunately for the reasons discussed previously.