a2141 820-01700 not boot

[ert]

Hello there, its nice to be here

820-01700 in a2141. Board with a signs of previously repair (t2 rebelled or reflowed - ohhhh.).
20V on charger meter but amps increasing step by step from 0A to 2.5A in a minute.
Ppbus 11.8V first than 20.3V and seems to be stable. In u7000 room, a "piggiess" c7026 and c7024 glow. Can't understand this case.
Could you help, please ?

All readings around u7800 seems to be ok,

 

[2informaticos]

First of all, welcome to the forum!

"Ppbus 11.8V first than 20.3V and seems to be stable."
Do you mean PPBUS_G3H (F7000/1), are you really sure???
If yes, change Q7030/40.

 

[ert]

First of all, welcome to the forum!

"Ppbus 11.8V first than 20.3V and seems to be stable."
Do you mean PPBUS_G3H (F7000/1), are you really sure???
If yes, change Q7030/40.

Hello,
I’m sure but its funny Yesterday came a1990 and had similar fault (on first view of eye). I said: impossible, day by day the same? Finally, it’s been just a faulty usbmeter and cable Have got brand new of both right now.
Any way, I have got PPBUS 12.6v now and no short (that what I see) and 20v on charger, 0A /no boot.
Diode mode (black to PPBus f7000/7001) gave .430 to l8102/la850 etc.
All V around u7800 I have got but can’t go into dfu. In Monday will try go dfu by short soc_force_dfu and pp1v8_awake. Will see but now (with keyboard) no success. Just dead board.
NAND looks good, no shorts (2.52v on pp2v5_nand_ssd0).
What can I check before try work u4770 with?

-thanks for help, have good evening bro

 

[2informaticos]

Use 1V8_SLPS2R for DFU, not AWAKE!

If someone already worked on T2, I'm afraid this board is wasting time...

BTW, write directly into bottom reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimetrs above.

 

[ert]

I thought it was exactly the opposite
I will, thanks.

 

[ert]

this is really strange to me:
the supply voltage is negotiable up to 20V. This may indicate that cd3217 are working (all four). I know, the right pair has priority (encoded i2c address) but...
I'm looking at soc_force_dfu --->>> 0V and .460 (diode mode /red to ground - not powered when test in diode mode // information for less experienced colleagues ). At this time, PPBUS is 12.6V. The problem is that at the same time soc_dfu_status is 1.8V (???) I don't know what's happening.
When I close the circuit soc_force_dfu --->>> pp1v8_slps2r the voltage on both pins is 1.8V (which is expected) but PPBUS drops to 12.3V (is it normall?). Of course, there is no reaction of the master computer to the patient's DFU status.
I conclude that the board with NO jumper is already in DFU mode (if soc_dfu_status has 1.8V) - is me correct?
Could this mean T2 death or is it a problem with TBT? To tell you the truth, I'm losing hope for this 820-01700.
Can you suggest what to do next please?

 

[2informaticos]

Solder a switch (5-10cm wire) over SWK003.
Maintain it pressed turning off the machine with power button.
It should enter DFU after 2-3 seconds.
Just play with these buttons, you should get it.

 

[ert]

Yes, I use swk003. Now, your suggestion about button play works, thanks. Next step of problem: I used revive (user data). „System can not be restored. AMRestoreErrorDomain 9. Failed to handle data request message (communication error, possibly usb disconnection)). (AMRestoreErrorDomain 0x9 (9)).
Question: is revive same as restore swiping data of u4770?

 

[2informaticos]

Did you try with 96W charger and battery connected?

 

[ert]

Yes,

 

[2informaticos]

Sometime revive failes, but restore can complete.
SSD will be erased, but data may be already lost.

If you flash/change SoC ROM, need to restore, not revive.

 

[ert]

Hello,
Same as above, same info about communication error when restore too. The difference is that, when start installing system (step 4/4) current goes up slowly 0A to 1.1A and seems to be frozen (20,1V) on 60sec than goes down to 0A. Funny is that after take off a skw003 switch, current goes slowly up to 2.80A but PPBUS has 12.3V again. Another new thing: when disconnecting a power (usbc) voltage drops to 11.8V ( ;-) ). Trolling me this board.
I thing I should start to beginning again.

 

[2informaticos]

"when disconnecting a power (usbc) voltage drops to 11.8V"
That's normal, dependes of the battery charge level.

You may have problems with T2, or CPU...

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