Mid 2018 A1989 very small amount of water damage

[Zeruo]

A small amount of water got into the charge port.

The laptop no longer turns on, no fan spin, no display. The photo shows the damage to the charge port. If I replace the port will this fix the issue.

I have a multimeter if that helps... I'm not too sure how to use it though so will need some help

There was also a small amount of corrosion on the board near the charge port .... I have cleaned this off with some isopropyl alcohol

Thank you in advance!

 

[2informaticos]

First of all, welcome to the forum!

That looks ugly, possibly spikes from VBUS to data lines.
You should check voltage and diode mode on all power rails; starting with PPBUS_G3H and 3V3_G3H.
And need USB-C meter to check input voltage.

Also need 820-xxxx board code, to see if any schematic is available...

 

[Zeruo]

Hi! Thanks for the reply.

I have ordered myself a USB-C meter.

I'm not sure where to find the board number.. where about a would it be located.

I do own a multimeter, but I will need help on how to use it if that's ok?

Kind regards

 

[2informaticos]

We first need to locate a schematic, if available.
Sometime doesn't exist and need to use another, closer possible.
Check on Internet pictures for 820-00850, 820-01041 and compare with your board.

 

[Zeruo]

It looks like it's a 820-00850.

I have tested it with the USBC meter and the photo attached is what I get.

I have replaced the USBC port and put everything back.

It still doesn't boot and no fan spin. But I get 20 volts from the charger.

Are you able to help ?

Kind regards

 

[Zeruo]

This it the readout I get from each side

 

[2informaticos]

Post exact PPBUS_G3H voltage (no battery).
Do you get 3V3_S5?

 

[Zeruo]

Hey how do I do that?

I have a multi-meter .. what setting do I need to use

 

[Zeruo]

I have the boardview schematic now I can see where ppbus_g3h is. Do I need to measure the voltage? If so how do I do that

I have discord as well if you wanted to add me... Dan H#3836

 

[2informaticos]

I asked about voltage, so yes; check on DC voltmeter mode...

 

[Zeruo]

Hi PPBUS_G3H seems to be 0.203 V to ground

 

[2informaticos]

So no voltage at F7000.
What is the exact voltage at R7020?

 

[Zeruo]

R7020 is 20V to ground .. kind regards

 

[Zeruo]

I didn't realise that I needed the charger plugged in .... PPBUS-G3H is 12.5 volts to ground.

 

[Zeruo]

I have gone through all of PPBUS_G3H and cant see any short on it. Been through them all on resistance mode. They are all 10+ at 200k setting.

F7000 has no short

R7020 has no short

 

[2informaticos]

You cannot have any short on PPBUS_G3H if gets 12.5V.
And do not waste time measuring the same rail in different points; how can you think will get different values???

Do you get any voltage at L7600/60?
Any pulse at least?

 

[Zeruo]

L7600 has 5.5 volts

and L7660 has 3.3 volts to ground

 

[2informaticos]

Then you should have more voltages on the board.
Post them for all big coils...

 

[Zeruo]

What are the coils sorry ?

 

[2informaticos]

Something like L7600/60; bigger, or not...