MBP 2013 15" 820-3787 no keyboard, no touchpad

[djty]

Device: Laptop
Brand: Apple
Model: MacBook Pro
Board number: 820-3787-06
Problem:

• no keyboard, no trackpad
• Fans Spinning fast

Hello everyone. The MacBook pro late 2013 keyboard is not responses even when trackpad is disconnected.
no reaction on KB, only power button andd ctrl alt shift, which are on keyboard connectore are separately on the KB pinout KB backlight is present the PP3V3_S4 and PP3V42_G3H one keyboard connector J4813 are present on keyboard
external USB keyboard works Should touchpad be connected to motherboard for KB to be working?

as 2EA side wide traces on the trackpad flex cable were broken which are restored, but anyways even connected or disconnected trackpad the KB is not working Could you please help me with the issue of no working TP and the keyboard?
Thanks a lot!!

[reformatt]

Keyboard does not work on these models without trackpad connected. There is a sensor on the trackpad, so CPU is throttled/fan speed max in it's abscence. Connect another trackpad and cable first to confirm, as from memory you need to remove the battery to gain access to it for replacement. No point doing that to find out it's not the trackpad after all.

[djty]

Thank you for your help!
Basically the new trackpad flex cable is replaced and keyboard started to work, but trackpad is not. Ordered new trackpad and it did not worked, the old and new trackpads still dont works. So user said will use it with the external usb or wireless bouse, so laptop assembled back with new battery, and works well, no fans spinning fast. because I could not find schematics and boardview on 820-3787-06 but only 820-3787-A I could not be able to measure resistos on the way, but only voltages, which were present.