[help] 820-01958 dead: 20v not switching

[mon2]

Review this power sequence chart which is applicable for your board:

https://logi.wiki/images/6/6a/820-01...iagram_LO2.pdf

[phantomEVO]

How? Ppbus_g3h is the first power rail…and it is not ok

[mon2]

Attach a known good battery. What is the voltage then of PPBUS_G3H?

[phantomEVO]

with battery and charger, ppbus_g3h is 11,5 and i have i have 20,27v @ 0,026 on both ports (i insert battery and then charger i have 5v, then i disconnect and reconnect the charger and i have 20v)




with battery only, ppbu_g3h is 11,5v




with charger only ppbus is 12,32v and i have 5v @ 0,046 on both ports

[phantomEVO]

I've changed u7800 and now i have pp3v3_g3hot at 3,29! but ppbus_g3hot still at 12,31

[phantomEVO]

u7800 ldo NOW:

PP1V1_SLPS2R 1,1v
PP1V8_SLPS2R 1,8v
LDO_CORE 1,49v
PP0V8_SLPS2R 0,79
PP1V2_AWAKE 1,19
PMU_LDO3_OUT 1,95v

basic voltahe on u7650

pin 23, 22, 12, 13, 29, 21, 4.

12,31
0v
0
0v
0v
0v

[phantomEVO]

ok now it is in dfu: can i try to fix it without losing data?

i can choose between

restore
update
prepare
reactive
initialize

[mon2]

No revive? Revive will be without user data loss.

Actions > Advanced > Revive Device

https://www.hoxtonmacs.co.uk/blogs/n...DDoKIrwjcJoOSX

[phantomEVO]

i have translated from my language...i think revive is reactive

[phantomEVO]

Unexpected device state 'DFU' expected 'Recovery' (Probably forced into DFU mode externally) [com.apple.MobileDevice.MobileRestore – 0xFAE (4014

[phantomEVO]

PP1V2_AWAKE 1.2V

PP1V8_AWAKE 1.8V

PP3V3_AWAKE 3.3v

PPVDDCPU_AWAKE 0.755v

PPVDDCPUSRAM_AWAKE 0.802v

PP0V8_SLPS2R 0.800v

PP1V8_SLPS2R 1.8v

PP1V25_SLPS2R_SMC_AVREF1.25

PP1V1_SLPS2R 1.1v

[phantomEVO]

i have the error with battery only, with power supply only with both connected

[phantomEVO]

could it be possible because of having tbt reprogrammed some post before?

[phantomEVO]

PP0V9_SSD0 but it is not shorted

[mon2]

What is the exact voltage to ground of PP0V9_SSD0?

Yes, try to reflash the TBT rom directly like before. Does that allow for this to work? Good job on the PMU replacement - you have more (bga) balls than I.

[phantomEVO]

PP0V9_SSD0 is 0v


i have no problem replacing even smaller chip....i would like to be good like you with the theory!!!!

SO DO YOU THINK THAT COULD BE A TBT ROM PROBLEM??? are you sure??? because reprogram it is a pain in the ass

[mon2]

Wait on the TBT rom for now. Review and consider the points of interest from this thread:

https://repair.wiki/w/MacBook_Pro_A2..._at_20V_repair

Report any mismatches. You are to review the SSD rails in diode mode, etc. since you have 0 volts.

[phantomEVO]

this is a totally different machine....i have not the same power rails...and i have 20v only if i connect battert power supply

[mon2]

Yes, I know. Just review the SSD0 details. Using the same posted values in diode mode, etc. Note the resistance they are mentioning in the article. Would you have similar measurements?

[phantomEVO]

PP0v9_SSD0 is ok

there is no PP2v5 rail

and about PP1v8_SSD0

i have 4 differret rail and according to open board data

PP1V8_SSD0_S4E1_PCI_AVDD_H
PP1V8_SSD0_S4E1_AVDD18_PLL


PP1V8_SSD0_S4E0_PCI_AVDD_H

PP1V8_SSD0_S4E0_AVDD18_PLL

are all ok