Surface Pro 7 EC

[ajbernasko]

Hello,
can somebody, please, help me diagnosing and issue regarding SP7? This machine is killing me

Once I plug it into the charger and press the button it turns on and immediately off due to the charger cutting off power.

I measured all the voltages / signals and it seems to get through the power on sequence into an S0 state with all voltages and signals present (it even goes as far as to display the Microsoft logo and starts reading from the bios), however after around 100 ms the charger cuts off the power.

I checked the charger and it seems fine.

Is there anything that could cause this behaviour?
Also, could a faulty bios cause this sort of issue (resetting the charger)?

Thank you so much.

Hi, I had same issue but after programming the EC chip(U3401) from a good one the laptop was not booting to the logo anymore but unfortunately I lost all my files, maybe you can open a thread and dump your ec bios hopefully someone can help. @SMDFLEA, @PESTE, @LAPFIX. I received same issue today and have not found anywhere to get the dump, however I have communicated to the customer whom I last fixed(stays nearby) so I can dump his EC bios one more time.

[Prott]

Re: Surface Pro 7 - turning off briefly, then charger cutting off

Thank you. I dumped the EC chip some time ago - here's the dump. Not sure if it is of any help.

Now I have another SP7 that was working before, but after replacing the screen (and a few sudden restarts due to an accidental press of the power button) it started behaving exactly the same - Surface starts for a second and then immediately restarts the charger.

It seems to be quite a common mode of failure, so it would be nice to have a fix.

EDIT: This dump is from the newer v2 board. Not sure if it works for the original v1.