820-00239 A1706 'Critical Update Required and no touchbar

[Roshon]

We've got a A1706 with no touchbar that is failing to'Critical update.
Also tested the board in a different housing and still the same error.

Not sure where to check next.

Just to add that the Macbook boots in safe mode

 

[2informaticos]

Any history available?
Check voltages and signals on both touchbar connectors.
Find proper test points on boardview.
Compare readibgs with good board, if possible.

 

[Roshon]

I GET 5V ON PIN 22 PP5V_SO_T139 pin 21 1.8v
PIN 20 PP1V8_SOSW_DFR 1.1V pin 19 1.1v
PIN 18 1.8V
PIN 16 1.8V
PIN 14 1.8V
PIN 2 dfr_touch_lid 0v

 

[2informaticos]

"PIN 20 PP1V8_SOSW_DFR 1.1V"
Are you sure?
As per schematic, pins 20 & 21 are tied together.

Check J4401 too...

 

[Roshon]

 

[2informaticos]

Did you check with touchbar connected?
What about J4401?

 

[Roshon]

i replace j4401 now it works thank you