820-01958 MBA 13" '20 A2179 - unable to enter DFU

[cruiser_]

I've got A2179 of unknown history - no liquid damage visible under microscope.

Macbook starts to an Apple logo, after a few minutes it either turns off or shows error screen (computer had to be restarted etc). Battery is shot (ripped).
I tried to DFU it. No luck with keyboard sequence - although I am not sure if keyboard works at all - wasn't able to 'D'iagnose or 'R'ecover.

Board on the bench... Both USBc ports negotiate 20V and current fluctuates a bit to steady out at around 200mA.

I jumped SOC_FORCE_DFU with PP1V8_SLPS2R. No luck, SOC_DFU_STATUS stays at 0V. DFU host does not detect connection.

Would appreciate some suggestions as to how to approach this case.

[mon2]

Disconnect the keyboard and trackpad. Test again. Any difference?

Review the resistance to ground with no power for each of the following rails as per the following article:

https://repair.wiki/w/MacBook_Air_A2...nt_draw_repair

[reformatt]

You should check the board first for any corrosion before you leap into DFU. Had a A2289 the other day where you'd get the Apple logo and it would shut down soon after. Had a shorted PP3V3_G3S_WLANBT power rail due to corroded cap C3724. It was hidden under the small flap covering the WIFI antennas.

[cruiser_]

Disconnect the keyboard and trackpad. Test again. Any difference?

Review the resistance to ground with no power for each of the following rails as per the following article:

https://repair.wiki/w/MacBook_Air_A2...nt_draw_repair

Board on bench.

Checked the rails listed there. All stable. I am getting a stable ALL_SYS_PWRGD/PM_PCH_PWROK/PM_PCH_SYS_PWROK/PLT_RST_L too. When connected via USB both ports negotiate USB speed, PID, VID, etc.

I looked at the board under the microscope, nothing suspicious found. Granted, I did not look under the metal shields.

[cruiser_]

A bit of an update... I flashed SOC ROM with T203 dump. The device came back in DFU mode finally (!).

Unfortunately the restore failed (IPD update / no touchpad). Turned out the flex is broken so cannot continue with the restore.

Thanks for looking

[M4n0l0307]

A bit of an update... I flashed SOC ROM with T203 dump. The device came back in DFU mode finally (!).

Unfortunately the restore failed (IPD update / no touchpad). Turned out the flex is broken so cannot continue with the restore.

Thanks for looking

Thanks Friend for Update !