A2179 820-1958 with burned out CD3217, no visible liquid damage

[Outofwhack]

Ive replaced one visibly blown CD3217 and reloaded the TBT rom and have both USB C ports now achieving 20volts but thats it - still no boot.

20volts 90mA with battery disconnected.
ppbus_g3h 12.3v
ppvin_g3h_p5vg3s 12.3v
pp3v3_g3h_rtc 3.3v
pp5v_s5_ldo 0v
pp5v_g3s 0v
p5vg3s_en_dly 0v
p5vg3s_en 0v (no enable issued by PMU to produce 5v)


PMIC LDOs are present
pp1v1_slps2r 1.1v
pp3v3_g3h 3.3v
pp1v8_slps2r 1.8v

PMU_PVDDMAIN_EN 0v

 

[2informaticos]

Did you try DFU?

 

[Outofwhack]

Ive tried for hours to get it into DFU mode with keyboard commands both inside case and with external keyboards and with battery connected with no luck.

Ive tried jumping SOC_FORCE_DFU (pin 1 R8010) line to PP1V8_SLPS2R (pin 1 C7840) with no luck

 

[2informaticos]

You should try soldering a switch between SOC_FORCE_DFU and 1v8_SLPS2R; use 5-10cm cables.
This will help you to force it.

 

[Outofwhack]

Just tried a switch with leads - still no luck getting into DFU mode. Verified SOC_FORCE_DFU goes from low to high.
Tried with battery and trackpad connected too.

 

[Outofwhack]

is there anything else I can try to get it to respond?

 

[2informaticos]

Many people have problems to get their macs into DFU.
You may need to test several times.
Also be sure to follow all the steps.

DFU Mode Restore (Macs) - LogiWiki

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