820-00923 a1706 5v no ppbus

hello got this with 0V on ppbus g3h not shorted. 5v 1.87amp on all ports
mess here, previously all chips got correct ldo voltage including 1v1 ldo on cd3215
so i checked parts on u7000/u6903/d6902/ theres no short circuit on this part.
followed from my previous post https://boards.rossmanngroup.com/threads/solved-820-00923-no-power-no-1v1-ldo.61493/
replaced u7000/d6902/u6903 just trying my luck here. this part also did from other shops.
still no luck . after this suddenly u3200/4200 this side my usbC meter is looping 1v1ldo still present also looping.
which is UB300/400 not looping (stable 5.19v 1.36amp) this time ub400 missing 1v1ldo after i replaced twice ub400 1v1ldo still not present
then wonder whats wrong. so i test ldo1v1 on ub300also missing so i replaced ub300 now both ub300/400 have 1v1ldo but also now looping/restarting same as
u3200/4200.
i didnt see any short/leaks on all related component,

voltages:
PP3V3_G3H ok

u6903
pin1 7.8v
pin2 4.8v
pin3 3.4v
pin8 4.8v
pin9 1.0v
pin10 5v
 
Last edited:

2informaticos

Administrator
Staff member
You've meant to say U3100 instead of U4200, I suppose.

Don't waste time with U6903 if already got correct 3V3_G3H.

Now the 4 CD3215s get 1V1 LDO and restarting?
Check diode mode to ground on all big coils.
What is exact diode mode reading at PPBUS_G3H?
 
forgot to mentioned 3v3_g3h is around 1.4v something before.

Now the 4 CD3215s get 1V1 LDO and restarting? YES


no short on bigcoils except this which is normal.
L7430/20/10 0.003
L7210/20 0.006
L7270/60 0.070

PPBUS_G3H 0.400 0.1V
 

Mac Tech

Member
measure continuity to ground at LB150 and L2950.

if you have a value on the multimeter, remove that coil and test the 20v rise
 
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