Chosen Solution
After replacing the battery, I’m having problems reconnecting the speaker connector to the motherboard.
Is it possible that at disassembly you removed the speaker AND the connector itself, as in —scraped the connector off the logic board itself when you pulled up on the speaker wire?
The speaker should be straightforward to connect back in its connector unless you have connector damage, or ripped the connector off the board (both are easy to do).
Check your board under magnification and post a picture if you can. The good news is that the speaker connector is a straightforward microsoldering job for your local microsolderer (or mail in logic board repair service)
