[HELP]a1990 820-01041 NOBOOT, STRANGE!

[phantomEVO]

Hi to all...820-01041 no liquid spill...3 usb ports stuck on 5v, the other board totally dead

strange thing is that i have 0v on fuse f3000....

how is it possible?

connector on board is good, no shorts on PP20V_USBC_XA_VBUS

i have also swapped usb-c flat with the one of the otherside with no luck...any hel?

Thanks

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

i would also like to add that i have not found shorts around charging ic

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

please help!

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

so first port on the left, 5v @ 0.172amp
second port on the left, 5v @ 0,033amp
first port on the right, 5v @ 0,030amp
second port on the righ, no voltage no amp (ampmeter stays off)



PP3V3_UPC_XB_LDO 0v on each cd3215

[mon2]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Test with known good type c connectors/paddle board.

Check the resistance to ground of the port that remains dark. That could be stopping the others from working.

What is the history of this unit?

Have not seen this model but follow the 20v article by @Piernov.

[reformatt]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Provided the USB-C connector isn't burnt etc, the most obvious target is the CD3215 on the dead port (or a shorted cap around it). If that one is dead, then the other won't go to 20V.

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

edit

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Test with known good type c connectors/paddle board.

Check the resistance to ground of the port that remains dark. That could be stopping the others from working.

What is the history of this unit?

Have not seen this model but follow the 20v article by @Piernov.

like i said before, i already check for usb c connector, swapping the one on the right, with the one on the left...

so you tell me i should change the cd3251 of the "broken" port.

just one questione: how is it possible that in the broken port i cant find 5v on the mainboard, even near the connector????

where can i find the 20v article? thanks

[reformatt]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

just one questione: how is it possible that in the broken port i cant find 5v on the mainboard, even near the connector????

CC1/CC2 are required from that controller to the charger for it to even enable 5V. The controller is supposed to then negotiate with the charger via PD protocol to get your 20V etc. So again, if there aren't any shorted caps around the chip, then it's most likely dead. Sometimes they get a hole in the top of them.

[mon2]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

https://logi.wiki/index.php/CD3215_Bootup_Sequence

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

CC1/CC2 are required from that controller to the charger for it to even enable 5V. The controller is supposed to then negotiate with the charger via PD protocol to get your 20V etc. So again, if there aren't any shorted caps around the chip, then it's most likely dead. Sometimes they get a hole in the top of them.

what is cc1/cc2?

[mon2]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Cc1 and cc2 are the contacts on the usb type c connectors. These pins are used to communicate with the external power adapter using a single wire communication (BMC format). Check their resistance to ground without any power. The esd tvs diode may be damaged on the pin(s).

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Ok now i have 5v@0,269 on all 4 ports...and 3,3v ldo on all 4 ports

now?

[reformatt]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

It's an A1990, so first thing to rule out is that the NAND's aren't shorted due to a failed U9080. Usually PPBUS_G3H is also shorted when that happens.

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

ppbus is not shorted...i've check all caps/inductance around u9080...no shorts! so what's next?

why should i don't focus on charing section?

thank you very much

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

i have all ldo's...

i have PPDCIN_G3H
i have TBA_VDDA (PPCHGR_VDDA)
i have PM_EN_P3V3_G3H (NC_CHGR_EN_VR1)
i have PP3V3_G3H

i can't find in schematic PP1V2_G3H_SMC_VDDC or PP1V2_S5_SMC_VDDC
i can't find in schematic PP3V0_G3H_AVREF_SMC or PP3V0_S5_AVREF_SMC
if it is PP3V0_G3H_RTC, i have 3,3v

i can't find SMC_RST, if it is TP_CHGR_SMC_RST_L, i have 1,7 and not 3v

[reformatt]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

Troubleshoot using the power sequence MON2 linked above. Some power rails won't come on till the T2 is running, and for that, you need functional NAND's to load Bridge OS. You won't get 20V until the T2 is running. See if you can connect via DFU to do a revive first.

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

yes i've used the link above...all ok until

smc_rst is 1,7 and not 3v...

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

i wouldn' like to miss data

[phantomEVO]

Re: [HELP]a1990 820-01041 NOBOOT, STRANGE!

what do you think gods?

@mon2
@reformatt
@piernov