Switch not work 14v and 0.41A

I need help with a somewhat strange case, they brought me a switch with a poorly soldered load pin, without the vbus resistance and a mosfet soldered in a place where it does not have one, it solved the vast majority of problems and is left with 14v of consumption and 0.41A. the cpu gets hot. I would like a guide on where else I can check if I have already ruled out any type of short in the 3v3 lines and some other key points on the board.

Have you checked this max77621 condition like voltages or corrosion?
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What is typical current on a 14V supply on a working board? I usually have to use a 5V supply as my USB ammeter does not like the nintendo AC adapter, so I’m unfamiliar with current draws on the higher voltage supplies

Sorry I don’t understand this, you talking about the USB port?

You talking about the current sense resistor? (next to fuel gauge) - if yeah, might be worth taking a very close look at the fuel gauge for damage / rework / alignment issues.

Which one?

Does the current initially drop to zero then back to 0.41A or is it 0.41A straight away and throughout?

such as?

I can see from your image prior rework of - 2R2 Inductor, USB, M92 IC, One of the speakers doesn’t look right, almost scorched, so I’d check it’s not dead short (think ordinarily they’re a few ohms) . If none of these were you then that’s what I’d check first, also possible is ram issues I suppose based on the prior rework in the area (assuming it’s bad prior work)

I couldn’t see any type of corrosion in that area, nor did it give me any indications and short

m92 is in good condition, I made sure there was no short and the voltages were correct, before placing the missing vbus resistor near the USB port the consumption was 5v 0a once the consumption was installed I made the change from 5v to 14v with this consumption of 0.41a

In the same way I already made sure that it is not in auto rcm

re-read what I wrote (look at the question marks and go one at a time ) :slight_smile: I can’t help if I don’t know :+1:

it stays at 14v and 0.41a all the time, it doesn’t go to zero

Ah ok, USB diode If I’m remembering right, given USB has been swapped and M92 IC (and I think fuse from what youv’e said) I’d imagine there was some issues here

Given this, I’d probably check the following,

Also, good to know, what’s charging current on 5V supply?

okey my bad,I call it vbus because on macbook and other things that I repair that rail would be equivalent to vbus in the usb type c pinout

1: check inductor 2r2 and it seems fine
2: rectify the usb port and everything bine without any short or lost line
3: I’m sure they changed m92 previously but it’s working normally and doesn’t have any kind of short or problem.
4:
The speaker does not have a short to ground, apparently it was just a glue stain or something like that

d+ 0.788 d- 0.788 in diode mode and the usb port not have open lines

You wanna be reversing your probe polarity too on these. And you wanna check both diodes in this case as well :+1:

I’m curious as to why they touched this to begin with :thinking: What’s the resistance relative to ground on it (battery disconnected) black probe on ground.

After this, I’m gonna have you measure your other primary rails to rule them out :slight_smile: