820-01521 liquid damaged

[drmacbookth]

Hi, I have an Air with liquid damage around Type-C ports. CD3215 (5V 0A ) had a short on one of the 3.3v lines and one got a bit warm, after replacement shorts are gone. Also no short on any of the big coils. Now I get 5.15v 0.02A and then switching to 5.02v and 0.26A and staying there. PPBUS is 12.29V, should be 12.6? What should I check next?

 

[2informaticos]

Do you get 1V1 LDO voltage at CD3215 chips?
3V3_G3H present?

 

[drmacbookth]

3V3_G3H is present
And I get 1.1V on C3104, is that the 1V1 LDO you mean?

 

[drmacbookth]

Note there was some corrosion on R3103, R3105 and R3109, i replaced them no shorts and resistance is correct, no change in charging

 

[2informaticos]

Each CD3215 must get 1V1 LDO, only when the charger is connected to corresponding port.
The other 3 LDOs are always present.

BTW, LDOs are clearly visible inside chip pin notations!

 

[drmacbookth]

OK, I measured as follows with charger connected:



U3100 (charger connected)

C3108 = 3.28
C3106 = 1.81
C3105 = 1.8
C3104 = 1.11

U3200 (charger connected)

C3208 = 3.3
C3206 = 1.8
C3205 = 1.8
C3204 = 1.1

Seems all LDO lines are OK. I have 3.29 on both CD3215 PP3v3_G3H_RTC lines as well as 5v incoming. Would you suggest try other CD3215's or are there other voltages that need to be present to create 20v?

 

[2informaticos]

Check if you get all SLPS2R and AWAKE voltages.

 

[drmacbookth]

The SLPS2R signals are there and so are the Awake: 1.1, 1.8, 3.3. I noticed the T2 chip getting hotter then the rest of the board by 5 degrees, is this normal or could it be T2 issues?

 

[2informaticos]

Test if it is recognized in DFU...