MacBook Air (2017, A1466, No power/orange-green light on)

[joeoffice12]

I have a 13 inch MacBook Air 2017 that does not show any life, however, there is activity from the MagSafe light going from green to orange and staying. Normally, this battery works perfectly fine and it can actually charge the battery as if I were to leave it alone it would change to just green, however, this thing does not boot up at all, I was told the computer was at 30% and then it randomly shut off.

Some voltages:
PPBUS_G3H - 8.5V
SMC_PM_G2_EN - 3.42V
PP3V3_S5 - 3.32V
PP3V42_G3H - 3.42V
PPDCIN_G3H - 15.18V
PP5V_S5 - 5.04V
PP3V3_S5_REG_R - 3.32V
PP3V3_S5_AVREF_SMC - 3.30V
SMC_RESET_L - 3.11V
SMC_ONOFF_L - 3.39V
PM_SLP_S4_L - 0v
SMC_S4_WAKESRC_EN - 0v

nothing looks out of the ordinary that might be burning or blown. Everything looks perfectly fine besides those 0v discoveries I made, please leave any suggestions!!

This is when using the official OEM 45 W MagSafe 2 charger.

[reformatt]

Test board on the bench with only LIO board connected with no battery. Board should auto-start when magsafe is connected. From what you've got above, you are getting to S5 state. PM_SLP_S4 needs to go high to advance.

So with these boards, you first need to establish whether you aren't getting PM_SLP_S4 at all, or whether you're getting it pulse high once or twice when power is first connected. If you get nothing, then you need to go through the PM_SLP_S4 pre-requisites. If it's pulsing once or twice that is another matter.

Use the power sequence for PM_SLP_S4.

https://logi.wiki/index.php/G3_to_S3..._and_Broadwell

[joeoffice12]

Board doesn’t start at all that’s the thing, even if it’s just stripped completely with the IO only being connected it does nothing.

i saw mentions of that checking for pulse but I’m still not too fully aware of that, could you let me know of more detailed steps, I’m still kinda new to this so bare with me haha.

thanks for your reply, looking forward to your response.

[reformatt]

Pulse simply means that it changes state from 0 to it's nominal voltage briefly. Most multimeters won't react fast enough to show the nominal voltage however, what you're looking for is some change in voltage from 0, hence 'pulse'. To see what level the signal or rail gets to, you need an oscilloscope.

If you are getting no activity on PM_SLP_S4_L, then you look at your pre-requisites. This page has a good write up.

https://www.it-tech.com.au/mac-q-a/pm-slp-s4-l-timing/

A common fault of these boards will have all power rails up to CPU Vcore pulse twice, then return to S5 state. Need to eliminate if this is the case as it's not fixable outside of reballing or replacing the CPU.

[kevingill]

Is there any corrosion on the board especially around the clock circuitry?

[joeoffice12]

I’ll definitely try that out, I did notice just the slightest bit of corrosion but it wasn’t really near any chips, I didn’t notice much of anything really.