820-00923 Touch bar PP20V is 5.2v

Don Anton

New member
Hi, this is liquid damaged. liquid has touch close to u3200.

I get pp3v3_upc 3.3v, pp3v3_g3h 3.3v.

Ended up replacing both u3200 and u3100. (CD3215C00) and q3200 still 5v.

What any other power rails need to be present to get 20v?

Thank you for your help.
 

Don Anton

New member
I get
PP20V_USBC_XA_VBUS 0.432v
PP3V3_G3H 0.324 V
PP20V 0.124 V IN DIODE MODE.
All of them near same reading
 

Don Anton

New member
Hi just an uodate.

I injected ppbus to F7000 and you get pp20v and cpu vcore. So i changed u7000 still no luck. only 5v on pp20v.also found C6905 burnt and replace the cap. I get 3.3v on pin 1. but some time i get 4.5v on c6905 pin 1. by thst time pp3v3_g3h goes to 2.3v or 2.7v.
 

2informaticos

Administrator
Staff member
You mentioned correct 3V3_G3H in the first post.
What happened, that you only get 2.3-2.7V now?
U6903 requires enable signal from U7000.

CD3215 chips have various power rails, 1V1, 1V8, 3V3, 5V.
Even cannot get voltage on any, you still must check diode mode on all.
Compare readings between the 4 chips and look for any strange value.
 

Don Anton

New member
Hi thank you for your reply.

I got first stage stable 3.3v on pp3v3_g3h. then I noticed 2, 3 times it went to 2.3, 2.7 v . now i get 3.3v stable. I get pm_en_p3v3_g3h from u7000.
on CD3215 i get 1.1v on c3204 , 1.8v on c3205, pp3v3_g3h and pp3v3)upc_ldo. But i dont get 5v in pp5v_s4_x_usbc. do we need s4 stage to get this?
 

Don Anton

New member
As i mentioned when i injected ppbus_g3h I get pp20v 20v and the CPU vcore. Is this normal even with bad CD3215? or is this ppbus_g3h iissue?

As this is 1TB, 16gb board I'm trying anyhow to repair this board. really appriciate your help.
 

Don Anton

New member
Hi 2info,

Finllay I fixed this and solved.

I thought to give a note here as the fault is bit strange and hopefuly this will use for some other technician.

I got pp3v3_g3h 3.3v and diode mode also fine (0.325v)
Some times pp3v3_g3h droped to 2.7v so I injecked 3.3v pp3v3 and i get 20v on pp20v. but nothing on D6902 or R6902.
then with out injecking i get 5v on D6902 and the pp3v3_g3h. Finally i found what ever voltage comes to D6902 pin 1 & 2 out put is only 3.4v . Replaced D6902 solved.

Again Thank you very much for your help.
 
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