A1989 missing unknown component

[reverendalc]

i have an A1989 2018 MacBook pro 13" 4TB3
it was completely raped by the previous "tech"
tons of screws stripped, standoffs broken, components knocked off...

there is a component missing that appears on the iFixit teardown MLB photo.. but is mysteriously absent from the .brd and pdf schematic.

please see attached photos. does anybody know what's going on?

[reverendalc]

Re: A1989 missing unknown component

if anybody has one of these, could you please look at the component markings and share?

[5chematic]

Re: A1989 missing unknown component

I would like to share this story, maybe it can help you clarify your issue, so please read this whole theat. a few days ago I removed the firmware chip from a A1707 model, and removed the password from it. soldered the chip back and everything went just fine. but sometimes no matter how good you are with electronics, I mean, how neat and perfect you do stuff, there is always something in the way.. so when I was installing the board back.. I ripped off a very very small component, and the problem was that I lost it for a few minutes! I mean, the small component. oh! not a problem I said to myself, and started to look at the boardview alone with the schematics. then I found myself lost in the boardview just like your picture, and I thought that the part was missing from the boardview. so in conclussion, even if you think that you are viewing at the boardview the right way, it might not. so after flipping and rotating the board a few times, the part was there. so if you have the boardview of that model, and also the schematic diagram, then you should be all set.

[reverendalc]

Re: A1989 missing unknown component

You are removing eeprom to remove password? That’s a lot of extra work.

Anyway, thanks for your story, but I am positive that I am viewing the board correctly, as you can see the corresponding parts.

[5chematic]

Re: A1989 missing unknown component

You are removing eeprom to remove password? That's a lot of extra work.

Yes, that's what I did. remove the chip then decrypt the image and remove the password. sometimes I don't have other options, that's when I have no choice but to do this task. I've been doing it since 2008. and sorry about your issue, wish I have a board like yours to share some info so you can resolve the problem. good luck with it.

[guruji]

Re: A1989 missing unknown component

i have an A1989 2018 MacBook pro 13" 4TB3
it was completely raped by the previous "tech"
tons of screws stripped, standoffs broken, components knocked off...

there is a component missing that appears on the iFixit teardown MLB photo.. but is mysteriously absent from the .brd and pdf schematic.

please see attached photos. does anybody know what's going on?

Ill check tomorrow and tell you which part as I have the same board what problem does your board have

[guruji]

Re: A1989 missing unknown component

hello ,
This is a T2 chip 820-00850 and there is no power all the ports are stuck on 5v. I have 3.3v okay smc supply_g3 okay and 12v ok. now my questions are
1) since this is with a T2 chip is it servicable investing time and efforts can this board be repaired as there are too many programmable devices and all in tandem with the big daddy T2
2) the cd3215c has black epoxy on it so has anyone replaced this chip on the same motherboard
3) i notice the pp1v8_slp2r keeps fluctuating not stable., but no short any where nor any water damage.
4) how do we know which ports from4 malfunctioning.

[guruji]

Re: A1989 missing unknown component

here you go my friend missing part

[guruji]

Re: A1989 missing unknown component

74LVC1G126GF part no for VN this is the buffer for spi function