Strange switch that won't charge or start

Nintendo Questions Nintendo Switch
1

Hi guys.
I repair things as a hobby, and I’m thinking of trying my hand at repairing a Switch for the first time.

I have a v1 switch that won’t start that I bought at a flea market.
It was sold because it started up but could only be charged occasionally, and charging was very slow.
However, when it arrived, it wouldn’t start and wouldn’t charge.
Even after replacing the battery with a new, charged one, it still wouldn’t start.

The TypeC connector was in a very shaky state, but only the cover was shaky.
When I tried charging it, I confirmed that voltage was coming to the fuse and M92T36, and when I measured the battery voltage, the voltage did not rise even after 10 minutes, so I thought that the charging IC was probably damaged, so I looked for where the short circuit was. However, I found a shorted cap near BQ24193.
ttps://imgur.com/a/OJVQPQt(Add h to the beginning of the address)

I also checked the cap near M92T36 and PI3USB, but there was no short circuit.

I suspect that BQ24193 is corrupted, but it also seems like an unrelated Cap.

The other board only has V2, and I’m having trouble figuring out if this is correct or where the cap is connected to.

This CPU board is HAC-CPU-21.

I am using machine translation, so please let me know if there are any mistakes.

2

That resistor is just 0 ohm so not really a “short” there.
What voltage do you have on the port fuse, 2R2 coil and big cap near BQ?

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3

Thanks for letting me know, there was no problem with that Cap.
I measured it and checked it while charging with the battery disconnected and it went back and forth between 2 volts and 2.2 volts.

4

2.2 volt on the cap or the 2R2 coil

5

I forgot to write down where I measured!
It was the 2r2 coil that I measured.
I have looked into the 2r2 coil in videos and other sources, but I think the voltage is low.

6

I also forgot to write down the voltage of the capacitors.
I guess I better go to bed soon.
cap was 15.2v

7

2R2 coil voltage also depends on your battery voltage, if your battery is low the coil voltage will be pull down accordingly. I guess you have a very low voltage/empty battery.

8

Thank you. The above measurements of 2r2 and cap were taken with the typec cable connected while the battery was disconnected.

When measured with the battery connected, the voltage at 2r2 was the same as the battery voltage. (3.9v)

When the battery was connected and charged, the voltage of 2r2 was the same as the battery voltage.

9

After connecting the battery, we check the voltage during charging and compare it to the BQ24193, which has no problems, and the BQ24193 seems to be fine, so we look for other causes.
The image below is a checklist for BQ24193, with the voltage on the outside and the diode test value on the inside.
ttps://imgur.com/a/Koa4ysk(Add h to the beginning of the address)
I would like to check MT92T36 in detail next.
If charging is not working, is there anywhere else to check?
Is there a problem with the USBC connector and the switch is not working?
(I have already confirmed that there is no problem with the battery)

10

BQ all values look fine. M92T36 is not easy tell whether good or not by just measuring diode reading, sometime it shits out even measured good diode reading. Measuring diode value is no harm anyway.
Plug-in charger with battery to measure current draw with type-c Ampmeter if possible.

11

I ordered a c-type amperage meter when the comments came in, but I lost it and had to return the defective one… LOL!
Anyway, I was able to measure the voltage with the defective one, so I wrote it down.
15V 0.045A and charging? It seems to be.

I decided to check the M92T36 when the voltmeter comes in, so I haven’t done the diode test yet.

When I turn on the power switch, the 3.3V line seems to be alive and trying to start. (I was told that if the M92T36, BT Wifi chip or BQ24193 is broken, the voltage will drop.)
However, when I connect it to the dock, the screen is dark, no response, and the display and backlight don’t seem to be working.
The memory and CPU are woozy and hot.
I guess MAX17050 is next in doubt…

I will now test the M92T36 before the new c-type ampere meter arrives.