Macbook A2159 (820-01598) PP3V3_S5 on/off

[Jenzo]

Hi, working on a macbook A2159, I think it has seen liquid but can tell for sure. It has been cleaned by a previous service I think.

Working of the boot sequence found here: https://www.logi.wiki/index.php/CD32...er_on_Sequence

All is fine until PP3V3_S5, it keeps looping on and off (0v => 3.3v => 0v =>..). No short on the line, tried looking with my heat camera but only the backside of U3900 seems to heat a little (33 degrees celsius), when I look at it with the shield still covering it nothing special. I'm reluctant to take of the shield, but it seems like that's the next step. Any advice on how to proceed?

Schematic and boardview included if needed.

Thanx in advance!

[Jenzo]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

Went over this again to be sure, and found that everything up to (and including) PCH_PWRBTN_L stays on for a few sec, and everything further until PM_PCH_SYS_PWROK pulses rly short, my multimeter barely picks it up. Except PPVCC_S0_CPU, or the other S0_CPU lines never seem to get any power.

Does this help in any way? Otherwise I'm gonna give this one up, client can't keep waiting hehe.

[mon2]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

These are not simple repairs. Client will probably run out and buy another one...

Using a suitable and proper rated power adapter?

Test with the onboard buttons @ SE030 / SE031.

[Jenzo]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

Yeah I already fear it'll be too expensive, but either way good experience for me.

Original 96w usb-c charger, confirmed working.

Never used these onboard buttons, I just have to bridge them to ground I'm assuming?

[mon2]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

These should be low profile / height pushbutton switches. If in doubt, post a close up pic but otherwise you should be able to just press on either to mimic the ON/OFF power button.

[Jenzo]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

Nothing there, I can see where they are supposed to be but they're not.

I see now this is the 820-01598-06 variant, assuming these don't have them soldered on?

[Jenzo]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

Any other suggestions? Otherwise I'm just gonna call it on this one.

[mon2]

Re: Macbook A2159 (820-01598) PP3V3_S5 on/off

Confirm the voltage of PP3V3_G3H_RTC to ground.