820-00840 - No PPBUS

[menatwork]

The board just stop work.
F4700 = 5.2V
F7140 (PPBUS_G3H) = 0.23V - DIODE MODE = 0.424
L7130 = DIODE MODE 0.415

 

[JohnB8812]

Voltage on PP3v3_G3H? 5.2 volts is your problem NOT PPBUS.

 

[2informaticos]

Check PP3V3_G3H, BUF_SMC_RESET_L, TBA_VDDA/P, TBA_AUX_DET, CHGR_ACOK.
Check diode mode on power pins of CD3215 chips.
Inspect under microscope if any of these chips has some very small hole on it.

Also look with atention at redriver circuit.
Is on the oposite side of CD3215 chips, near the USB-C connector.
Be aware, it doesn't figure on any schematic/boardview; is the PI3USB32224B chip.

 

[menatwork]

PP3v3_G3H 0.23V

 

[menatwork]

I'm sorry. I just realized i post the wrong board model.
The board i'm working is 820-00845

 

[2informaticos]

What machine model?
That code is very strange...
Isn't 00045, or 00875?

 

[menatwork]

Model: 820-00045

 

[JohnB8812]

Figure out why no PP3v3_G3H first is it shorted to ground? Just fair warning, these ALWAYS end in dead CPU at some point, so it could have a faulty CPU as well or a CPU that fails weeks after you fix it.

 

[menatwork]

No short to ground on PP3v3_G3H.

 

[2informaticos]

Change U4700.
If no result, is better to return it.
In fact, not worth to spend time on these boards at all.
Wiil finally end with dead CPU, or SSD...