820-01700 runs from battery, not charger

[Dusten04]

I am not going to lie to you, the title makes this sound easy, but I'm not thinking its that easy.
820-07100

Board History:
Battery died, client wasn't able to charge. Does show the dead battery symbol when you plug it in. (I am using a known good OEM 96watt adapter) No liquid

I unplugged battery, plugged in charger, 20v with a quick spike to 300mA then down to about 20mA

So, to explore this a little more, I connected a known good battery as well (this one was also close to depleted, as when I plugged the board into this battery, it also showed the dead battery symbol. However, with this battery, the current started to rise, and the battery was charging at about 4-4.5amps. The unit turned on normally.

Weird, I thought, as I know this unit will turn on, with no battery, with a 96watt charger.

So I started taking measurements in line with this chart from logi.wiki

https://logi.wiki/images/6/6a/820-01598_Prometheus_Power_Sequence_Diagram_LO2.pdf

This is where it gets weird for me. I am getting all the measurements I would expect, up until PP3v3_S5. It's not present.

This coming from the PMIC, my first thought was "maybe bad PMIC"

My hesitation comes from the fact that it will turn on, and charge with a known good battery. (even though it was also depleted enough not to turn on the computer right away, like the original)

My thought is, if it's a bad PMIC, why would it turn on with a known good battery, and not only the 96watt adapter

Thanks for the help in advance.

 

[2informaticos]

Some machines require battery presence for proper work.
I'm not sure about this board in particular.

Is the battery test charging?
If machine works good with that battery and charges it, then don't waste more time on it; just get new battery and close it.

 

[Dusten04]

The 01700 does boot with a 96 watt

I have already done about 10 of these boards. So... There is definitely something wrong with the board

 

[Dusten04]

“Is the test battery charging?”

As I mentioned in my original post, test battery is charging at 4-4.5 amps. So yes, thats charging

 

[2informaticos]

Still not clear.
Does the machine work properly with both charger and battery connected?
I don't think the client will use it on charger alone, without battery.

 

[Dusten04]

Just update for anyone who cares if maybe their client will want to use the machine with a stone-dead battery like it was designed.

The solution: SMC issue, Flashing T2 ROM, and DFU restoring fixed the issue.

 

[2informaticos]

Thanks for feedback...