Moving target - power & battery issues

Picked up 2015 a1465 MBA 11". Had issues. Came with multiple batteries, one swollen and no good.

Got it home, pulled back cover and battery, grabbed a brand new 85w adaptor andtried it out. Managed to get MBA to run, but it would die and shut down after 5 minutes or so (stopwatch, I timed it).

Disconnected battery, it would start and run just fine. Seller had wiped the HD, so I did full reinstall of OS. Tried battery again, nothing. Everything else worked, so I guessed IO board. Installed known good new working IO board, amd a brand new replmnt battery. Then it would not see battery, but no longer shut down at random. Runs fine on power adaptor, so i also upgraded to Monterey.

Now it sees the battery. Charges the battery. But will not run on the battery. If I pull the pwr cord, it shuts down immediately.

I completely disassembled and cleaned everything (w/alchohol). Seller said it was never wet, but that does not explain some of the white fuzz I found growing on logic board. Small amounts, but several. Cleaned thoroughly and reassembled.

Now it works same as before (only on power adaptor), same issues. But it added one new problem - even though power is working to run MBA and to charge battery, now the charger lights do not come on.

Track pad, keyboard, monitor all work just fine.

I'm thinking I have no choice but to replace logic board. SMC chip is my guess.

I have done PRAM, SMC resets, held power button for 10 secs with charger connected and disconnected, all things that helped earlier in the diagnosis. No difference.

Any suggestions before I toss a logic board in it? Thanks in advance for your help.

I have pulled the logic board. Found some small spots of corrosion. Cleaned thoroughly with alchohol with magnifying headset on.

I'll download that and get a screenshot.

Cannot figure out how to paste photo into this forum, sorry. Stats from Coco Batt: cure charge 4992 mah; full cap 5052 mah; 98.8%. Design cap 4800 mah. Cycle count 1. MacOS battery status good. 28,4 degrees C. charging with 0 watts. Power adaptor connected. History 2023-05 99%.

Stock battery indicator says power source: power adaptor. Batter fully charged (100%).

Hope that helps. Thanks again for any advice or direction that anyone can provide

I do not now which is the SMC chip, I can only say that I cleaned it very thoroughly

By the way, I am typing this on the very MBA right now. AS long as it stays plugged in, everything is OK. I just worry that it might overcook the battery. By the way, I am typing this on the very MBA right now. AS long as it stays plugged in, everything is OK. I just worry that it might overcook the battery.

Prior to the IO board replacement, Apples menu bar battery icon showed power but did not see any connected battery.

This symptom went away when I installed the new IO board and battery.

This is why I titled this "moving target".

Thanks for your reply!

I have checked battery and connections. Have two good batteries (one brand new, 1 cycle, the other almost new, 70 cycles). MBA sees them both, charges them, and give accurate status and voltages, confirmed by system info.

Every time it is disassembled, I re-cleaned battery and other connections.

I noticed that light on charger issue seemed to arise after the removal of IO board flat cable. I received new cable today, and lights are again lit and working, reflecting correct status on the charger plug.

Every symptom is fixed, except it dies as soon as power cable is pulled.

Fixed:

- no longer shuts down at random

- lights function correctly on power plug

- sleeps when closed

- reawakens when lid opened

- will reboot during updates and continue

It literally does everything a 2015 MBA should do, except stay on when unplugged.

I have a known good tested logic board on the way. I will report back when that is installed.

In the meantime, any suggestions are welcome and worth trying.

=== ===