Switch dont Turn on, no charge

Hello,
I come from Germany and try to express myself as best as I can.
My Switch Model (XAJ) 5 years old no longer loads or starts.
The console was a dock-only console, so I rarely took it out of the dock.
I connected a charging tester and have a charging voltage of 0.0 amps.
I measured the battery and it is at 4.1 volts.

I then looked at the board on the front side for shorts and found a few. To the left of the BQ24193 chip there was one.
I then removed the BQ24193 and the short was still there.

Then I also had shorts at both Maxim chips.
I’m really at a loss and am hoping to get the console to work because there is important data on it.

I tryed to upload pictures but get this “An error occurred: Sorry, you can’t embed media items in a post.”

I hope my English isn’t too bad to understand me.
Best regards

Are these your shorts?

I have a short in all the marked areas on the front side of the board(BQ_VSYS_B)
But not all of them on the back(BQ_VSYS_A)
Im not sure what of these are fuses or capacitor but the 2 above 583(in a circle) do not have a passage on both sides.
The first 2 of the 3 to the left of 188 also dont have a passage on both sides.
And on the right the 376/520 is not shorted as well.
The rest have a passage on both sides.

i attached a picture and those with the X or overdrawn are not passaging on both sides.

At all red markings vsys line appears.
The goal is to find the culprid which is shorting vsys to ground.
Caps which have no contact to ground and have two different readings on their ends are fine.

I would check visualy for obvious damages/decolorations/cracks in the different spots.

Thanks, I’ll see if I can find any optical errors.
I’m just a bit overwhelmed, are all these square things like capacitors?
Or just this big ones?
That i can measure whether those has ground and 2 different readings.

No. There are caps, resistors, inductors and other components.
If a cap fails, it normaly enables a direct contact between it two sides.

In this case you will not find a failed cap by measuring, because most caps on this line have one side on ground and the other side at the ‘grounded’ vsys line.

If you are lucky, there is a spot with a decolorated or cracked cap. If no damage is visible I would try to find a heatspot by injecting voltage at this line.

I’d say the odds are only marginally more likely that caps fail dead/direct short to ground, maybe 6, or maybe 7 out of 10, they can and do fail “soft” short the other given times too… which I can attest… all just depends on the failure mode. and of course there are caps which only “fail” (reveal themselves) in active short scenarios (albeit rarer), both of the latter are a pita to find :slight_smile:

I’d be careful here. OP hasn’t even determined / stated what the resistance of the so called short to ground is, as well as (and I’m assuming) a misunderstanding as to other “shorts” on the board (which raises red flags) … we also don’t know for sure if this is a Mariko revision (presumably it is with “XAJ” ) which apparently can have the diode present on SYS which may give the illusion of a short on some meters.

Hi totally unrelated to the problem here but i would like to ask where this image is from. Where would i be able to get one as well.

I think in search for a short, I would expect a failed ic or a shorted cap in this line.
There for I over simpilfied and wrote that a failed cap is shorting.

The diode is a good point. I didn’t think about it.

@Kazyro: So please check if you have a board version with a diode (very tiny component between bq ic and the big inductor) and check resistance to ground on vsys.

@Ddvl: The image is made by myself and is a diode mode map from a Erista version.

I spotted something suspicious on the front.
It looks like a small piece of the capacitor has broken off.
So I’m talking about the chip that’s at the bottom left with the three capacitors and it’s the top left one.
You almost can’t see it, and it also seems like the Maxim chip underneath got some heat from exactly that spot.
So i would remove that one copacitor and check again for shorts right?

Measure the resistance to ground first, black probe on ground (screw hole pad / USB pad, or whatever) red probe on the postivie side of the cap in quiestion, note the reading, [if it’s short] remove the cap and see if the said short (if applicable) has gone.

The capacitor had a short circuit, I definitely removed it and the whole board no longer has a short circuit.
The only thing that happened to me was that the Maxim chip shifted when it heated up. I’ll have to re-solder it, I hope it won’t be that difficult.
Have a slightly shaky hand, i can solder but thise little parts are really difficult