Check diode mode to ground on U6703 inputs, w/ and w/o keyboard connected.
To properly check amy key:
I prefer to use
To properly check amy key:
I prefer to use
-
For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.Subscribe Now
820-01700 2019 A2141, right shift key, left option, control, and caps lock led not working
- Thread starter SanDiegoHB
- Start date
SanDiegoHB
Member
thanks for that
in diode mode, input pins 1-3 all register ~1.83v with and without keyboard connected
in diode mode, input pins 1-3 all register ~1.83v with and without keyboard connected
Please, read how to properly check diode mode:
boards.rossmanngroup.com
HOW TO collection
I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...
boards.rossmanngroup.com
SanDiegoHB
Member
ok, thank you,
input pins 1-3 all register ~.485v with and without keyboard connected
input pins 1-3 all register ~.485v with and without keyboard connected
Try another keyboard.
Do you get 1.8V at pin 1 of J6701?
Do you get 1.8V at pin 1 of J6701?
SanDiegoHB
Member
different keyboard, same result. diode check is done without power connected, right?
and yes I get 1.8v pin 1 of J6701
and yes I get 1.8v pin 1 of J6701
All the other keys tested in browser, as above mentioned?
SanDiegoHB
Member
yes, done, all other keys work
Remove DZ6701 and test again.
Be sure to have good solders and traces at U6703.
Be sure to have good solders and traces at U6703.
SanDiegoHB
Member
all three are ~.472v after DZ6701 removed
Change U6703 again.
Be sure to get good solders and check its traces to KB connector.
Be sure to get good solders and check its traces to KB connector.
SanDiegoHB
Member
the kb connector is just reverse of this, that area is in perfect condition. I found another U6703 and re-soldered it. The input pin diode measurements are all .482-.485v. However, I do not get any voltage on the corresponding pins of the keyboard connector. DZ6701 is still removed
SanDiegoHB
Member
so I re-soldered DZ6701, and checked the kb connector pins and still 0. I found another DZ6701 and soldered it and still 0v for the three inputs on the kb connector. I get 1.8v still on U6703 pins 7-9, and basically still 0 on pins 1-3.
Possibly bad contacts at J6701; maybe crap underneath.
Check voltage on similar pins of keyboard connector from another board.
Check voltage on similar pins of keyboard connector from another board.
SanDiegoHB
Member
contacts look clean
I compared U6703 voltages on a board from a working system and found that pin 6 should have 3.3v but our board in question is almost zero. this must be significant, yes?
I compared U6703 voltages on a board from a working system and found that pin 6 should have 3.3v but our board in question is almost zero. this must be significant, yes?
Yes, reset output should be high.
That's the reason I suspected U6703.
Just in case, check R6752 and R8014.
On the other board, all 3 inputs have 0V?
That's the reason I suspected U6703.
Just in case, check R6752 and R8014.
On the other board, all 3 inputs have 0V?
SanDiegoHB
Member
yes all three inputs on the board from the working system are also 0V. after my last message I checked out R6752 and it was low and it basically broke off while I was testing, so I replaced it and now 3.3V on pin 6 reset output of U6703. Also R8014 now has 3.3V on both pins. but still no voltage on the kb connector.
SanDiegoHB
Member
I was going to test R6703 and it's missing. let me replace that and post back here