[help] 820-01958 dead: 20v not switching

[2informaticos]

I was wrong thinking that voltage comes (ONLY) from L7690.
In fact U7650 is not enabled yet; at this point the voltage comes from U7800 (VOUT_RTC).

 

[phantom]

and so? your conclusion? and what about ppbus_g3h at 12,32v?

 

[phantom]

wasn't the low voltage of ppbus_g3hot the main and first problem?

 

[2informaticos]

You may have problems with some component connected on 3V3_G3H rail.
Which may sink more current than U7800 can deliver.
Or just a bad U7800.

STOP worrying about PPBUS_G3H level.
Your T2 is not even properly powered; how can it control PPBUS_G3H???

 

[phantom]

ok sorry! so tomorrow i will change u7800...but if i don't have luck with u7800? what can i do? is 3v3_g3h directly connected with cd3217? don't you remember whats happened on those controllers under thermal camera?

 

[2informaticos]

Which CD3217 chip did you see connected to 3V3_G3H???

 

[phantom]

I don’t know…I Just wondering if there is a Connection between 3v3_g3h….

 

[2informaticos]

I also make confusion between 3V3_G3H and 3V3_G3H_RTC at the beginning of the post; already connected.
Do not follow my errors...

 

[phantom]

3V3_G3H_RTC Is present and it this 3,3v …so should I but a new u7800 or not?

 

[2informaticos]

Is the next step to try.
I recommend you to get it from scrap board.

 

[phantom]

pp3v3_G3hot 3,29 ROCKSTEADY WITH NEW PMU! ppbus_g3h still 12,31

next step?

 

[phantom]

u7800 ldo NOW:

PP1V1_SLPS2R 1,1v
PP1V8_SLPS2R 1,8v
LDO_CORE 1,49v
PP0V8_SLPS2R 0,79
PP1V2_AWAKE 1,19
PMU_LDO3_OUT 1,95v


basic voltahe on u7650

pin 23, 22, 12, 13, 29, 21, 4.

12,31
0v
0
0v
0v
0v

 

[2informaticos]

Should be now recognized in DFU.

 

[phantom]

yesssss! and now!!!can i try to fix it wihtout lost data? how?

 

[phantom]

i can choose between

restore
update
prepare
reactive
initialize

 

[phantom]

trying revive i have this error


Unexpected device state 'DFU' expected 'Recovery' (Probably forced into DFU mode externally) [com.apple.MobileDevice.MobileRestore – 0xFAE (4014

 

[phantom]

PP1V2_AWAKE 1.2V

PP1V8_AWAKE 1.8V

PP3V3_AWAKE 3.3v

PPVDDCPU_AWAKE 0.755v

PPVDDCPUSRAM_AWAKE 0.802v

PP0V8_SLPS2R 0.800v

PP1V8_SLPS2R 1.8v

PP1V25_SLPS2R_SMC_AVREF 1.25

PP1V1_SLPS2R 1.1v

 

[phantom]

i have the error with battery only, with power supply only with both connected

 

[phantom]

PP0V9_SSD0 is 0v but not shorted

 

[phantom]

Just at the beginning of the problem, i've tried to reflash the tbt rom with a dump found online...could it be the problem or not