MacBook Pro 13-Inch 2020

[nix9]

Thank you for the schematics. I have a machine with a burnt CD3217.
The system ran until the battery was depleted after the issue. Is there any way I can charge the battery using an external power supply?
On the charge control board, there are two large pads where the battery is connected.where I measure 8.57V. Would it be ok if I simply charge from this pad?

[nix9]

Re: MacBook Pro 13-Inch 2020 — 820-01987 (A2289), 820-01949 (A2251)

Thank you for the schematics. I have a machine with a burnt CD3217.
The system ran until the battery was depleted after the issue. Is there any way I can charge the battery using an external power supply?
On the charge control board, there are two large pads where the battery is connected.where I measure 8.57V. Would it be ok if I simply charge from this pad?

I removed the connectors of the battery control board and the large screw connecting it to the logic board.

The pads, where the battery connects to the battery control board were covered in hard epoxy for insulation. I drilled through this layer to reach the solder pads underneath. I measured around 8.57V here (so the battery was completely empty). I soldered two cables and recharged it through a bench top power supply with 900mA max current. This is what you get normally from USB3.0 but probably less than max charge rating of the battery but I didn't want to take the risk. I recharged stepwise incrementing from 8.57V up to 12.6V while checking the temperature of the battery just in case. It took a few hours so that the current reduced to 500mA at 12.6V which signalled me that the battery is charged to a good degree. I measured 11.57V once I detached the external power supply.

So here the battery is now had a good level of charge. I reconnected the battery control board. But it does not turn on.

In summary, charging the battery from outside didn't let me power on the system when my CD3217 (usb power control) is defective.

Here I remembered that, for the battery power to switch, the chip needs to communicate with the SMC. Probably due to the defect, the turn on command is not sent to the battery control board.

Probably there could be a way to fake this command or play pull some pins up/down to turn on the chip to turn on the battery power.

Or it may simply work if I connect the power supply to the logic board directly.

This still needs to be investigated. The problem is that, I couldn't find the schematics of the battery control board. The pins of the controller chip is also covered in glue, I don't want to destroy my battery or logic board in trying to do this.

For the moment I ordered a new CD3217, which will arrive in 2 weeks.

Will keep you posted.

And if you have ideas feel free to submit. Just posting all this to help someone else, because it seems to me that this CD3217 problem is a recurring thing. I've already seen several others having this chip burned in the same way.

[mon2]

Re: MacBook Pro 13-Inch 2020

Hi. Do you have a USB type c meter?

What is the power delivery contract on this logic board? If you have a defective cd3217, the logic board will be unable to negotiate the 20 volt contract. Each and every cd321x controller must be working to power the logic board and charge the battery pack.

You can also check the voltage to ground of ppbus_g3h which should be the output of the isl9240(?) on this logic board.

Post the measurement.

[nix9]

Re: MacBook Pro 13-Inch 2020

Thank you for the guidance and offer to support. I don't have a USB C measurement device but I don't think I need one. See the attached photos, CD3217 has a hole burned on it. I don't think it will generate the 20V for the logic board or charging.

What puzzles me though was the fact that even after I felt the burning and smoke the laptop continued to run. I shut it down after the smoke and let it cool down for half an hour, tried to restart and it restarted with a warning about USB port not working. It worked until the battery was completely empty.

This gave me the idea that if I would recharge the battery from outside that it would boot. But it didn't boot. I am guessing that the battery controller was in a state to enable power output to logic board. But once the battery was completely depleted it needed an external stimuli to enable the output.

Anyway, I will replace the burned CD3217 as a first step. I am hoping this would solve the problem. If not, then I would definitely need your valuable expertise.

[mon2]

Re: MacBook Pro 13-Inch 2020

Wow. Yup. NP.