Nintendo Switch , NO POWER, already checked for M92T36, shorts under CPU

PURP:730 OHM
YELLOW:14.6 OHM
BLUE:5.32 MEGA OHM
RED:10.4KOHM
These are the resistance readings

Ok cool. Red and Blue look good. Yellow seems a little low though. What’s the resistance to ground on the R2R coil?

After i posted the picture above, which seems like corrosion, the 2R2 coil is shorted. i think, that’s it. (Resistance is 0.00ohm and it is shorted to gnd (beeps))

Ok, so we have a short on the SYS rail. Last time I had one of these I injected voltage and looked to see what got hot. If you have a microscope, it may be worth going around the board looking for damage / cracks on some of the tiny chips. On mine it turned out to be the small chip just below the SOC on the front of the board, and there was visible damage once I looked at it. I am secretly hoping @Severence will join in here to remind me what else lives on the Sys rail. :smiley:

i do not have the tools to inject the voltage on the rails. but i will see if any other chip is phisically damaged

It may be worth following this thread:

It shows a number of the common culprits.

i saw lots of suggestion from @Severence, might be helpful, hoping to see him in here.

Hey,

SYS rail shorts are typically due to a failed BQ IC but it’s not exclusive. I would just double check you are measuring resistance releative to ground and not directly across the coil though and if so after let me know specifically what the resistance readout is, then you can go over the points Calvin highlighted in that post at the other areas of the board that this rail shows up and see which area represents the lowest reading which will give you a better idea as to where the culprit lays (BQ IC for example) after you can remove the suspect and see if the short clears.

Hope that helps :slight_smile:

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Hi severance, thank you for coming in and help. The reading of the rail that i gave (which are PURP:730 OHM
YELLOW:14.6 OHM
BLUE:5.32 MEGA OHM
RED:10.4KOHM)
is from the ground and not from the coil.

i do not have any dc injector tool, should i see only the resistance?

I’m doing that, the lowest resistance point, should me give very low resistance, i will tell here where the lowest spot resides.

Schermata 2021-09-28 alle 22.38.23
The one wich is horizontal is giving me 0.00ohms

Schermata 2021-09-28 alle 22.42.21
This one, next to the BQ ic is OL

No worries :slight_smile:

As Insomniac said, these rails seem fine, I’m guessing yellow is slightly low is because this is a Mariko board?

Which would be normal if your measuring across the coil, try putting one of your probes in a screw hole pad ground plane :+1:

That’s fine, you haven’t got a short to ground on your SYS rail :slight_smile:

im trying rn

it is a HAC-CPU-20

that’s mean that the cpu is not fried ?

it now gives me 11 Mega Ohms.

inserting the probes into the grounding holes, it gives to me 2 Mega OHMS

Can you take a picture of the IC below the SoC as I would expect HAD-XYZ for Mariko.

no just means your SYS rail isn’t shorted to ground, SoC may be fine but bit concerned about your readings on yellow if the board is not a Mariko revision

Yeah that’s fine :slight_smile:

Can you take a photo of your M92 install so I can inspect?


So it’s not Mariko unfortunately

Seems to be evidence of reflowing everytwhere which decreases it’s chances :frowning:

It’s hard to tell with all the flux residue but I would probably give this board a good scrub in some IPA and inspect the M92 and BQ IC as they appear slightly crooked but bit hard to tell atm :slight_smile:

surely ill’ do it and post the photos of both of them




here they are, tell me if i still need to scrub with the ipa

It’s really hard to tell, I’m guessing you dont have a microscope? Even the super cheap ones can be very useful for getting a good view of the connection around these chips.