Shorted and burnt touchbar FPC connector A1706 / 820-00923-A

[StinkoPachinko]

Hello,

I have started undergoing my first ever MacBook logic board repair. I am having an issue in which one pad (PP1V8_S0SW_DFR) on this "J4402" connector is reading 2.3 in diode mode. Where I believe it should be reading around 0.56 (Donor board reference). I had to do two trace and pad repairs on pads 22 and 20. Pad 22 is reading correctly but pad 20 and 21 and other various components linked to these pads are reading 2.3. Will it be fine to throw a new connector on or should I keep digging around?

 

[2informaticos]

First of all, welcome to the forum!

Let us know if you've checked all the lines in diode mode with RED probe at ground.
Also check continuity between U4404 and J4402.

 

[StinkoPachinko]

First of all, welcome to the forum!

Let us know if you've checked all the lines in diode mode with RED probe at ground.
Also check continuity between U4404 and J4402

Thank you!

There is continuity in between J4402 and U4404. When you say check all lines you mean trace all of PP1V8_S0SW_DFR correct?

 

[2informaticos]

I meant if you checked pins 20 & 22 in same manner; red probe at ground.

BTW, write directly into reply box, instead of clicking Reply button.
Please, maintain forum aesthetic...

 

[StinkoPachinko]

My apologies, here are some measurements. Thank you for helping me thus far.

J4402:
20=2.3
22=0.46

J4401:
15=0.57
17=0.57

R4480:
2.3

R4481:
2.3

R4485:
2.3

CC704:
0.57

C4401:
0.57

CC706:
0.57

CC705:
0.57

C4471:
0.57

U4404:
1=0.57

R4491:
0.49

R3918:
0.57

R3917:
0.57

R3916:
0.57

R3915:
0.57

 

[2informaticos]

"J4402:
20=2.3
-----------------
J4401:
15=0.57"
How is this possible?
You've said to have continuity U4401/J4402; isn't the same power rail into your schematic???
Please, put some logic on your job.

 

[StinkoPachinko]

Imagine paying $30.00 and explicitly announcing this is my first repair to only be helped by an absolute prick. Pad 20 has been burnt up ... I did a trace repair and connected it to pad 21 which then they shared 2.3. I have removed the trace and pad repair but instead of reconnecting it for a second time I took to this forum only to be helped by an ass wipe. Thanks for discouraging me in this project I will look for help else where

Overall solely because you and your condescending attitude I will be immediately cancelling this $29 expert help bull shit.

 

[2informaticos]

I told you to check continuity and you came back saying to have good continuity.
Then you've posted readings which denote no continuity.
If you don't post accurate information, we can't help.
All the replies are based on the information you provide.

Sorry if you feel offended, is not my intention.

 

[StinkoPachinko]

Look no worries perhaps it's a language barrier and not ego. But you could have taken another approach to correct me instead of "use your common sense". Common sense told me that pin 1 for U4401 beeped when I touched pin 21 on J4402. Then took my measurements. But the measurements I provided last night are accurate and so was me checking the continuity between U4401 & J4402. So again I apologize for my very novice mindset but if you could perhaps enlighten me a little bit in regard to diode readings or what have you I am all ears. I would also understand if you no longer wanted to reply at this point for how stale these post have became.

 

[2informaticos]

You MUST get same diode mode readings to ground at pins 15/17 of J4401, as pins 20/21 of J4402.
Of course, you MUST check in the same manner; red probe connected to ground.

Once you get the traces and pads repaired, connect touchbar and check again in diode mode.
This way discard a short caused by touchbar itself.
Be sure the new connector is properly soldered.