829-3435-B (MagSafe Power on?)

[KC Micro Tronix]

I have a 820-3435-B board. I am used to turning on a board by just attaching the MagSafe and watching the green light come on and the machine power up. This one is a bit strange but it may just be that way and I don't know better.

When I power it up it works perfect. While in the OS I shut down. When the machine powers off I remove the MagSafe and reattach. Green light, then no power. PM_PWRBTN_L is at 3.3v. I can attach the MagSafe as many times as I want and it does not auto start but if I pull PM_PWRBTN_L to ground it fires right up. And each time I remove and attach the MagSafe after I do this it works perfect. Only if I shutdown in the OS do I have to do this. This seems normal but at the same time it doesn't.

Before I figured out the PM_PWRBTN_L I pulled the SMC and reballed it. Cleaned the elephant skin pads thinking there was a SMC issue.


How is this supposed to work?

 

[2informaticos]

All iCore machines turn on automatically when charger is connected, if no battery present.
Also these boards do the same if battery is there, but wasn't properly turned off; like pressing power button 4s.
Once machine is turned off from OSX (software way), board doesn't start when charger is connected and battery present.

 

[KC Micro Tronix]

This is just the bare board on my bench not in a MacBook. When booted up it does not show battery. when shut down and I power bounce the MagSafe it will not start unless I pull power button to low. If I remove MagSafe power for 10+ seconds and reconnect it will start.

 

[2informaticos]

Do you have the board without battery connected?

 

[KC Micro Tronix]

yes. The board is not in a macbook. It is naked sitting on the bench. Does not even have a keyboard on it. Just a USB connection

 

[2informaticos]

Then normally should start by itself every time charger is disconnected/reconnected.
Could be the one which doesn't properly turns on without battery.
But if battery is not detected (when connected), there is an issue for sure.
Try first known good working battery.

 

[KC Micro Tronix]

I think I am chasing a rabbit hole here. If I disconnect MagSafe for 2-5 seconds it works perfect. Tried a known good working board had same results. I only recently started booting bare boards all the way into the macOS on the bench and shutting them down.