Battery not charging, magsafe orange battery detected
I bought this MacBook on eBay, worked fine first couple of days. Then went to restart it last night and it would chime and turn off right away, happened a few times until I held the power button down until Apple logo came up.
When booted, connected charger but it would detect the battery and not charge. I had 32% battery power. Now it's on 18%, once it's dead I won't be able to do anything
MacBook also running slower than normal, did not happen when I got it.
Reset SMC/PRAM and no luck. Tried swapping out DC board, magsafe port, battery from another similar MacBook, same issue. It's the logic board.
I'm sure it charged when I got it, done nothing to it except put it on and update to MacOS Sur. Now this issue. Seller refusing to accept a fault. I don't know history of whether water damaged previously.
What can I check to fix this on logic board please?
Ran diagnostics got PPP003 error.
Pictures from coconut battery attached: