Acer CB5-312T

[Dinneke]

da0zsemb6f0 rev F

not charging USB-C stays on 5V schematic available quanta_zse_rev.1a_

any thoughts?

[mon2]

Re: Acer CB5-312T

Can you link or post the schematic?

Original power adapter?

What is the history?

Tested with a known good battery?

[Dinneke]

Re: Acer CB5-312T

Just stopped charging

Battery works after external charging

Power adaptor not orginal but likely to work

[mon2]

Re: Acer CB5-312T

The adapter is critical and if with less power, the logic board will be throttled and charging will halt.

Test with a suitable adapter.

Next step is to review the schematics.

[Dinneke]

Re: Acer CB5-312T

schematics

[mon2]

Re: Acer CB5-312T

Does your adapter support 45W or more?

20V 2.25A

[Dinneke]

Re: Acer CB5-312T

The adapter is critical and if with less power, the logic board will be throttled and charging will halt.

Test with a suitable adapter.

Next step is to review the schematics.

it is solid on5V

[mon2]

Re: Acer CB5-312T

It is possible that the BMC communication for the power delivery are not working to negotiate the power delivery contract.

Remove all power. Meter in diode mode. Review the usb c pinout and check the diode mode readings for CCx pins.

[Dinneke]

Re: Acer CB5-312T

Does your adapter support 45W or more?

20V 2.25A

yes 60W

[Dinneke]

Re: Acer CB5-312T

CCx pins:both 0.168 with red to ground otherwise open

i did get suddenly 15V after remove battery and reconnect

[mon2]

Re: Acer CB5-312T

CCx pins:both 0.168

Sounds low. Have not had a chance to review the schematics but check if there is a TVS diode on this line. If yes, carefully remove it and then check the same CCx diode reading to see if it is higher in value.

Note that CC1 is for one side of the USB C connector blade; CC2 is for the other side of the USB C connector blade.

Either can then communicate with the power adapter over this single wire communication.

[Dinneke]

Re: Acer CB5-312T

There are TVS but seems good

[mon2]

Re: Acer CB5-312T

Here are some known good DIODE mode readings from macbooks that make use of the USB C interface:

USBC0_CC1 Default d 0.588
USBC0_CC2 Default d 0.569

USBC1_CC1 Default d 0.584
USBC1_CC2 Default d 0.584

If you see a TVS diode on the line with the low diode reading, remove the TVS diode and test again to see if the measurement is higher.

[Dinneke]

Re: Acer CB5-312T

Never mind, the solution is near

Its totally working

[Dinneke]

Re: Acer CB5-312T

BAT_ENABLE _L was the cause, not looked byond that, simply added R699

[mon2]

Re: Acer CB5-312T

Nice! Strange that the battery's BMS was not supplying this pull-down status upon docking to the battery connector.