I posted some details on the I2C bus that should get you started.
One thing that I find interesting is that the log you posted shows a failure for ALL the devices on the bus. If there was a connection problem, say to the head or the interconnect only, you should still see successful communications with the control PCB’s accelerometer.
That would lead me to think there is something loading down the clock or data lines somewhere.
You can quickly divide and conquer by disconnecting the head and see if communications come back for the remaining devices on that bus. If not, try again after disconnecting the interconnect board (the plug in the upper right corner of the photo in the article linked to above). This will help narrow down which board has the bus problem.