820-02098 Keyboard not typing, liquid dmg

[GoobyPlzz]

Looking for a way to source a new chip for the UT101 spot. Above removal of the chip that was there it completely broke in half and fell apart (yes I know, throw tomatoes). The caps were all replaced with new caps now and all that is missing is the chip. L16A030D215 is what is written on it. All other features with the computer work as intended. No random reboots, trackpad works, no throttling or lag.

Any help or guidance would be great.

 

[2informaticos]

First of all, welcome to the forum!

UT101/2 encrypt keyboard information and send it to trackpad, through I2C bus.
So need to replace UT101.
These chips have firmare, but probably work any from other M1 model.

 

[GoobyPlzz]

First of all, welcome to the forum!

UT101/2 encrypt keyboard information and send it to trackpad, through I2C bus.
So need to replace UT101.
These chips have firmare, but probably work any from other M1 model.

Hi there thank you for the welcome!

Is there somewhere I can get these chips aside from a donor board? And is the chip literally called UT101?

I appreciate your help thank you.

 

[2informaticos]

The chip code is PCAL6416A, in QFN package.
You can only get it from scrap boards.

Same chip is used in older Macs, like A1502 and A1398, but in BGA package; useless here.

You can find QFN package in other M1 model, like A2338.
It is also available on T2 models, like A2251, A2289.
Just open schematics and search in pdf for "PCAL64"; then (if found) be sure it is HWQFN package (not BGA).

BTW, write directly into reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above.
Please, maintain forum aesthetic.

 

[GoobyPlzz]

Thank you very much. I'll do just that.

 

[GoobyPlzz]

Low-Voltage Translating 16-bit I2C-bus / SMBus I / O Expander With Interrupt Output Reset Registers Controller IC (NXP, PCAL6416AHF / L16A, QFN-48 Pin)

Low-Voltage Translating 16-bit I2C-bus / SMBus I / O Expander With Interrupt Output Reset Registers Controller IC (NXP, PCAL6416AHF / L16A, QFN-48 Pin)

www.mobilesentrix.com

Would something like this work?

 

[2informaticos]

For that price, you can try.
But not sure if has correct firmware loaded...

 

[GoobyPlzz]

So unfortunately after soldering the chip on the keyboard still does not function.

This is a personal device now so I'm not going to give up even if I have to be patient on a solution

 

[2informaticos]

Check if both UT101/2 get correct power.
Also check voltage and diode mode at I2C_KBD_SCL/SDA.
Be sure RT110/1 are good.

 

[GoobyPlzz]

So I reflowed the chip and replaced a cap that wasn't showing ground and the keyboard is now functional.... except the return / enter key. Trying to look through the boardview now, I see there are special call outs for Right Shift and Left Shift, but nothing that says "return" or "Enter". I feel like I'm very close.

Correction the Return, G, S, {,},| keys do not work. I tried a replacement keyboard and the same issue occurs. I'm wondering if this is a connector issue or something else.

 

[2informaticos]

When more keys are not woeking, very likely is a problem related with one row, or column of keyboard matrix.
Unfortunatelly, no keys distribution on the matrix available.
You should check all KBD_DRIVE/SENSE lines.
May have problems with JT200, or trace continuity until UT101/2.

BTW, for full test of keyboard, search on Google by "keyboard tester"; choose any one you like.

 

[GoobyPlzz]

I wanted to update you, I ended up reseating the chip again and made sure all pads made contact, and I'm happy to report that keyboard is completely functional now. Thank you very much for pointing me to the right direction.