M5PaperS3 wrong charger -> magic smoke

[felmue]

Hi guys

even though I read the warning about not using certain types of chargers with M5PaperS3 I managed to do so anyways.

Suffice to say, M5Paper released some magic smoke and wouldn't start anymore.

I cracked it open from the back (as I think the eInk display is glued in) to get access to the board. (I do not recommend doing that as it is a destructive process.)

With the eInk display and touch disconnected I started to inspect the board.

I found the charger IC USB-C protection diode pack being dead from the look of it. I removed the charger IC (as it is not strictly needed to run) I replaced the USB-C protection diode pack and found the MosFet IC getting pretty hot. So I removed the MosFet as well and injected some voltage (4.2 V) after the MosFet which revealed that the 3.3 V regulator took some hit as well. I replaced the 3.3 V regulator with a similar one I took from an M5Atom.

With two ICs MosFet removed and the 3.3 V regulator replaced M5PaperS3 took a reasonable small amount of current. I also measured ok voltages for the eInk display so I dared to reattach the display and touch screen and yo and behold - M5PaperS3 is alive again.

Now I need to order some replacement ICs MosFet.

You can see the opened M5PaperS3 and the dead ICs here.

Thanks
Felix

[ajb2k3]

@felmue thanks for taking the time to write up about it

[felmue]

Hi guys

while I am waiting for the replacement on / off MosFet to arrive I was able to put in a temporary fix - I found a similar MosFet in an old, broken MacBook Pro. :-)

Thanks
Felix

[kuriko]

@felmue
magic trick!

[felmue]

Hi guys

Update: M5PaperS3 fully restored and as good as new. :-)

Thanks
Felix