820-0149-07 5v

[PCOKAY]

Hello,

I have this T2 board not boosting 20v.
I found some moisture near J4801 just under, UPC_W_Reset, pad is almost destroyed.

When i plug type-C on all port i get 5v @0.25A; i just have one port oscilating, reseting, the port near oxydation actualy (just near top of J4801)
T2 ,U6903 and L6901 and are heating at 30° ~~.
CD3217 are not heating.

U8800 has a strange spot with moisture that i cleaned but not heating...
Please find photos attached.

Any lead please?

 

[2informaticos]

"UPC_W_Reset, pad is almost destroyed"
That is not a problem, is just a test point.

Please specify the CD3217 which reset the power meter.
Also check diode mode to ground at L9020/30/80.

 

[PCOKAY]

Hello and thank you,

CD3217 is U3100_R just near nasty moisture.
L9020 & 30 : 0.374 and 0.314
L9080 : 0.330

Just to be sure it's this the one with cable attached on the picture.

 

[2informaticos]

Possibly corrosion under U3100_R, or even bad chip.
Check diode mode at C3105/6/8.

 

[PCOKAY]

c3105: 0,511
6: 0,540
8: 0,510

Thank you, that's what i was thinking. I'll change U3100R and i'll report you.

 

[PCOKAY]

Hello,

I change u3100r 2 times and u3100w, same result still reseting fast on one port. take a look at the video please::

https://www.swisstransfer.com/d/c701ead1-32ac-47c2-aa20-e672bb232894

Maybe there is a short somewhere....
Any more idea?

Ps: i reflash ub260 & ub3060, same results

Thank you.

 

[2informaticos]

Check if boosts to 20V with battery connected.

 

[PCOKAY]

Hello,

No boost with battery, sadly...
P5VG3S_EN signal is missing
I tried DFU again, just in case got 4042 in revive and restore mode.
Maybe nand is dead? the hole on U8800 is suspect...

Looks like this problem but it's not a macbook air :

https://repair.wiki/w/MacBook_Air_A1932_Not_turning_on,_missing_P5VG3S_EN_signal_repair

Any sugguestion?

 

[2informaticos]

Bad NANDs shouldn't stop boosting to 20V.
I saw boards boosting to 20V with 2V5_NAND power rail shorted to ground.

You may have problems with T2, U7800, or still something bad in USBC area.
Actually all USBC ports have the same behavior?
Check their LDOs.

 

[PCOKAY]

U3100R is still rebooting 0 to 5v very fast (2-3 seconds up).
U3100W reboot 0 to 5V slowler approx 10 seconds
U3100T & U3100X doesn't reboot stay at 5V
LDO 3.3v et 1.5v are ok on all CD3217.

I find something interesting, if i remove U3060 (rom chip) i observe the same behaviour on the other side of the board.
Slave reboot fast and master reboot slowly...
I switch bios just in case one was dead (with reflashing write bios on each) still no luck.

 

[2informaticos]

Did you get TBT ROMs from working board?
We can't trust too much the files uploaded by chinese.
When possible, save the dumps from working boards...