820-4924-09 no keyboard (power, alt, cmd, works)

[tjulie]

Hi there,

I have an issue with a 2015 MBP - A1502 (slight water damaged) which after ultrasonic clean i replaced the DC board fuse and now works well except for the keyboard which has got me stumped. everything works including the trackpad and i have fitted a new trackpad & trackpad flex cable but all keys on the keyboard is not working with the exception of the (power button, ctrl, cmd, alt) which works just fine. Have tested new keyboard as well.

Test points on keyboard connector:


Pin 4 (PP3V42_G3H_TPAD) = 3.42v
Pin 5 (WS_KBD_ONOFF_L) = 3.3v
Pin 30 (PP3V3_S4_TPAD) = 3.3v

Any ideas on what to test / check next?

Kind Regards

 

[dukefawks]

Check power to U4820/30. Also check the data lines to the trackpad I2C_IOXP_SCL and SDA. Make 100% sure you trackpad and cable are good as that is the most common cause.