A1706 820-00923 Critical Update error

[hgoncalves]

Hi.

I've an A1706 820-00923 with an Critical Update necessary error.

Already disconected touchbar and webcam but got the same result.

With S-UEM2 J8500 EDP Tester, all values are normal.

In safemode it boots.

Can you help?

 

[2informaticos]

Any history available?

Check J4401/2 voltages and signals; compare with good board.
Sometime need to change U4200.

 

[hgoncalves]

Hi.

Don't have other good board to compare.

I've replaced U4200, but with same result.

 

[2informaticos]

Check in diode mode at least.

https://openboarddata.org/?a=showboardsolutions&bpath=laptops/apple/820-00923

 

[hgoncalves]

HI.

J4401:
MIPID_DATA_CONN_N = 0.540 (should be 0.752)
MIPID_DATA_CONN_P = 0.540 (should be 0.745)
MIPID_CLK_CONN_N = 0.548 (should be 0.755)
MIPID_CLK_CONN_P = 0.547 (should be 0.755)

J4402:
PP1V8_S0SW_DFR = 0.530 without touchbar conected, and 0.470 with touchbar conected

All other values seams preaty close

 

[2informaticos]

"0.540 (should be 0.752)"
Not necessary true.
Measuring with different multimeter on the same board, or other similar board, you can't expect same exact readings.

Did you test with known good touchbar?