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.
Clean board, sometimes when the battery is disconnected and connected again trackpad and keyboard works fine for a few hours or days, but it always comes back with no trackpad and keyboard.
Thanks, when it happens even at login screen no trackpad and keyboard and no boot menu option.
So if the trackpad cable goes bad keyboard doesn't work?
Recently you helped me fix an Air with similar issues but that mode the keyboard and trackpad connect via the same cable, on this MBP they connect via different cables.
MBP came in with the problem, I did some measurements, put the board back in and it works again, this has now happened a few times in the course of 3 months.
Is not easy, as you have a random issue.
You can test continuity for I2C_IOXP_SCL/SDA lines between motherboard and trackpad board.
For that, you must identify corresponding pins, because TP flex is not 1 to 1.
Even then you can get good continuity and still having problems.
I recommend to test 2-3 TP cables and inspect J4802 connector.