820-3435 only charging on 85W PPDCIN intermittent unstable

[G.Beard]

Was liquid to q7010.

Plug in an 85W charger it will charge the battery and power the machine but the MagSafe gets very hot.
Same with known working IO board.
Machine powers from battery.

With a 45W Apple charger:
Sometimes PPDCIN fluctuates by about half a volt.
PPBUS sometimes fluctuates by 2 volts.
3V42 is always stable.
When the rails are intermittently unstable like this it will not power on.

Then sometimes ralls are all stable but PPBUS is sitting at 8.25V
Green / Orange
OS shows charger connected but does not charge.

I have randomly attacked and replaced the 6259, Q7010, IO board, Inrush limmitor, Q7155

I'm sure this is a simple problem, but I'm just not getting it.

 

[dukefawks]

PPBUS should be 8.6V without battery connected. See if anything around ISL6259 gets warm too and check PPBUS voltage.

 

[G.Beard]

No man. Nothing gets hot.

So now when I plug any wattage charger in I see green / orange and the OS knows and shows the charger is connected. But it's not charging. The battery is fine.

 

[SMMRepair]

Had this problem on a 00164, turned out to be Q7180. Replaced it and issue resolved.

Edit: Just saw you said you replaced it; check continuity for all traces for these components, and make sure ISL is soldered well.

 

[dukefawks]

Checked resistance between 17/18 27/28 of the ISL? Q7130 and Q7180 are also suspects.