Nintendo Switch - No Power / No Charge

They are indeed :+1: they all seem good.

So it does indeed seem to be exclusive to the SYS rail…I mean unless there is some other obscure rail which is shorted to ground which is indirectly connected to SYS.

Sorry to do this, but can you remove the BQ IC again, and take that same measurment at the 2R2 coil and see if this high short clears?

Pretty much every other IC on this rail after this is BGA so it’s the simplest option at this point.

Alright, BQ removed, 2R2 is reading around 320ohms, a negligible difference.

Further, removed M92 as I was curious, with both BQ and M92 removed the 2R2 still reads ~320ohms.

Hmm how about we remove the 2R2 inductor and measure SYS elsewhere and see if the problem is up or downstream, though, I think pretty much everything else is downstream but cant hurt to check in case one of the BQ caps is bad.

you can find SYS plenty of places downstream, the main PMIC > the test pad just below the inductor where you were reading 4M ohms (I think -from memory) several caps on the other two max ICs below and to the left of the SoC, the 8316 IC etc etc

Hopefully it’s localised. This might be the best approch failing the above, removing anything which can isolate a BGA IC from the SYS rail and see if the short clears.

Take it this was with the 2R2 coil removed?

Oh, and this is Mariko, bear with me and I’ll let you know what’s next

Yep - 2R2, M92 and BQ all removed still.

Shame, I’ll look over one of my Mariko boards and see what can most easily be done to isolate some of these BGA ICs from SYS.

I could be wong, but from memory, Mariko boards are typically 5K to ground from SYS, on Lites which have the diode present at the BQ IC 300ohm is actually a normal reading in one polarity… which might be giving us a clue

Thanks mate - I don’t have a Mariko board here to test either, much appreciated :slight_smile:

Hey man,

I had a quick look and removal of the inductors I had in mind wouldn’t truly isolate the ICs from the SYS rail to rule them out, only 50% which wouldn’t be concrete enough to say they weren’t causing the issue.

Here’s the location of the inductors anyway if you want to try anyway, then after removal see if the 300ohm short to ground has cleared back at the 2R2 coil… though I don’t think it will.

Take a close look for any junk/bent pins in the backlight connector or LCD connector, it’s feasible if that was the case it could subsequently pull SYS down via the respective IC, that being the 8316 IC via the LCD conn or UXYZ (Backlight IC) via the bcklight conn.

If that’s not the case, my best guess would be junk under one of the BGAs on this rail. Might be a good idea to measure resistance to ground like earlier at the coils and surrounding components of the Max IC below the SoC, this is the most prone to liquid damage and would be my first guess.

Unfortunately 300ohm is too high to generate any meaningful heat, else I’d reccommend hooking up your PSU to this rail at 1V (no greater, in case there is a crossed line elsewhere) which leaves the good old fashioned… pull every IC on this rail, though reball experience (stencils, solder paste etc) is needed :frowning:

Can you update the status tl:dr. because the original issue from OP it was 99% bq ic then the m92. Problem solved. So lmk if you haven’t figured it out.

Game Guys - Houston

Hi Severence, thanks for all your help in trying to isolate the issue. Unfortunately I’m going to have to give the device back to the customer, it’s not economical for me to continue to spend time on it. Yep, it’s a bummer but it happens… really appreciate your help. Hopefully some of the info in the thread can help someone in the future!

No worries man :+1: and completely understand, sometimes you just gotta let these things go