820-0165-A slow, doesn't turn on automatically

[djdblaster]

History:
- water damage (I don't know how much), but 2 red marks are visible (1 removed though)
- SMC area was reflowed (glue not completely removed)
- PPBUS_G3H is 8.57V
- PP3V42 is 3.43V
- battery shows 35% health, no water damage visible, could be just worn battery (forgot exactly how many cycles, but I think more than 600)

As for the laptop, it starts when I hold Shift-Power after 5-10 seconds. In OS it is slow, mouse works normal however.

Doesn't start automatically when charger is connected.
Doesn't react when Power button is pressed.
J4800 is clean.

 

[djdblaster]

[No message]

 

[JohnB8812]

Yeah being someone messed with it, forewarning this one could really suck. The slowness is likely a sensor issue. First try a known good trackpad/trackpad flex, keyboard, battery, and I/O board/cable if possible to rule out a hardware issue.

 

[djdblaster]

I've disconnected everything. Should it start automatically when charger is connected?

 

[JohnB8812]

Yes it should. Does it? AS LONG AS it is an OEM magsafe these 2015-17 boards are VERY VERY picky about the charger.

 

[2informaticos]

It should, but it only starts in SMC bypass mode in your case.
Post A/BMON sensors output voltage.
Check exact value for R7121/22 and R7151/52.

 

[djdblaster]

"A/BMON sensor output voltage" while it's on? I gotta grab another keyboard to turn it on then.

R7121/22 and R7151/52 measure good, including pins on ISL.

On PP3V3_S5_AVREF_SMC I get 16 Ohms. (Marked in attached picture) Doesn't sound right?

It leads back to U5110, which is responsible for SMC Reset "Button". I get 0.4V on PP3V3_S5_AVREF_SMC. So first check caps on that raiil since damage is around SMC area and better yet, they're not even changed. Whoever worked on before, probably didn't think it mattered?

 

[2informaticos]

PP3V3_S5_AVREF_SMC shouldn't have such a low value.
Remove the caps first and next U5110.
If still low resistance, then reball SMC; you may have luck to be only crap underneath.
You can try first a reflow with quality flux...

 

[djdblaster]

I've got an original charger.
PP3V3_S5_AVREF_SMC back to its normal state. C5021 was bad and replaced with new one.
Everything else works now.
Thanks!
Mark as solved please.