Switch OLED not booting shorted caps

Hi guys, I have a Switch OLED issue that is puzzling me, I attempted to mod it but there seems to be a shorts on the board.

For example near the fan connector the two caps are shorted to ground and when battery is connected and device is powered on, this area gets very hot.

There’s also a short to ground on the P13USB cap which I have removed and short remains.

Things I’ve tried so far:
· Removed two caps near fan connector - short to ground still there on their pads.
· Removed P13USB - nearby cap is still shorted and two caps still shorted.
· Removed M13 chip, shorts still there, then replaced M13 chip and shorts are still there.

Please advise if you think I can do anything, I’m thinking next I’ll remove the BQ chip to see if short goes away but I’m open to suggestions.

It seems your going down the path of a lot of beginners and one problem bleeds into another and then potentially creates a secondary problem and so on and so forth.

Don’t know the caps your talking about specifically, but it seems as though your looking for shorts to ground on your meter with battery/power connected to the board which is a no no

Again not sure if your measuring while the battery is connected but if your seeing the short to ground present here (3V3PDR) with the battery disconnected then the process is pretty much the same as the last like x10 thread topics in resolving Switch modchip woes.

This all ties back to the first point :frowning:

Search the forum (or elsewhere) and gain some knowledge in regards to electronics / troubleshooting so you can more easily identify or present your findings :slight_smile: pretty much all these kinds of topics seem to devolve into me basically saying the same thing over and over (I’m like a broken record :wink: ) and sometimes into teaching very very basic electronic troubleshooting techniques where we assume you already have the knowledge.

Thanks for reply, no I’m not testing for shorts while battery is connected apologies if it wasn’t clear. Shorts are there without battery connected.

1 Like

I can show photos but I can’t upload to the forum or share links so :man_shrugging:

This is another one that is routinely asked here so I’ll let you figure it out :wink:

Check out those other recent threads, there is something i ask all people to do (relating specifically to the modchips) first things first before proceeding, after which i ask for rail measurments and so on.

After, feel free to post that image :+1: and I’ll take a look, might just be the cap specifically at fault :man_shrugging:

https:// imgur .com/a/byfkqu7

I’ve uploaded some photos at the link above

3.3v main line short, check if 3.3v present on picture 1 when power button press with battery plug-in

Thanks @jkyoho where specifically should I check on photo 1 for 3.3v?

the two caps you circled in red

It’s a bit pointless checking for voltage, though I am assuming you mean there is a dead short to ground (?) in which case I’d imagine it’s virtually zero (volts).

Either of the caps you’ve highlighted, being the fault themselves would be an interesting failure mode (though not impossible) - if you flush the area with IPA you should be able to see what is most likely the cause, either the chip or one of the caps (based on what’s boiling off quickest) the the IC itself can in some cases (in your scenario) be misleading (given it’s the source)

Though, I would hope you’ve disconnected the modchip, or at a minimum it’s power line/s from the board prior to any of this…

Also, maybe just a trick of the light, but the audio IC looks off, something about it

With battery connected and powered on and multimeter set to 20v DC I get a read of 0.10v on both caps.

Some observations with the audio IC, it gets progressively warmer when device is powered on I guess because of its mass it is slower to heat up than the caps.

Mod chip is removed completely, including dat0 adapter. It’s one of the first things I’ve done to find the cause of this issue.

Looking at the board schematics there is a short to ground on the pads highlighted and on the resistor(?) https:// imgur .com/a/cHf424D

Also used some IPA and observed that the IPA was sizzling under the 77801EWP bga chip near the two caps and it was hot to touch.

As expected. Battery disconnect then, resistance to ground?

Right, so as expected either that is your problem or it’s getting that hot due to the insane current draw (this IC is the source for this rail presumably) - You should probably refrain from connecting power to the board (or should have done so yesterday :wink: ) to avoid potentially damaging the board as a result of the heat :+1:

Somone else will have to confirm for me as I don’t have an OLED board handy but is the MAX 77801 being used in place of the “ENXX” IC for 3.3V rail generation ? or is this some other rail?

I didn’t know there was true board schematics?

Not sure if its against the rules to link the schematics but they can be found on gbatemp. Agreed, I’ll keep the board powered off.

I can remove the MAX77801 to see if the short goes away, but looking at a video of a near identical issue: https:// youtube .com/watch?v=oybLHsejoMo the outlook does not look good.

Post away :slight_smile: they look user made whatever the weather, whatever it is

Can do, or, maintain a consistent ground, Measure the resistance to ground on this rail (at those caps) and note the reading and then maintain your ground and find the same 3.3V rail at/next to your EMMC, if it’s lowest at the EMMC then that’s likely the problem :frowning: (Which makes sense in relation to the modchip)

The schematics are located here https:// files.zzattack .org/img/console/switch/oled/xzz/ and here https:// files.zzattack .org/img/console/switch/oled/xzz/ I’ll try what you suggested and get back to you

1 Like

ah, so these aren’t schematics, these are basically static “boardview” images. While they are excellent (much like @Calvin ones also) they aren’t a true boardviews, though maybe he is in the process of creating one, I mean he seems to be going layer by layer here… be a bit of a shame if he isn’t as the work and process is largely the same in creating a .brd file (or similar) … that is assuming he hasn’t already, all i can see is images.

Regardless, they are super helpful, thanks for sharing

1 Like

I guess that the pictures in the link are from xzz. I’m sure that they rebuild the ciruits from layer scans and made a propper boardview with net names. This are still no schematics, but very usefull to see and search for specific connections between pads, pins, ics…

1 Like

This would be super helpful, though I can’t find them as yet.

At Aliexpress or XinZhiZao.vip you can purchase limit access for 1, 3, 12 month or lifetime.
But I’m not sure what is exact included in those access.

1 Like