I just swapped the lowercase and battery on my 2016 12” retina MacBook. (I previously successfully swapped screen assembly.) All connections seemed solid and it buttoned back up without a problem. But when I plugged it in it began to start up in internet recovery mode, the. just went black. Upon trying to start again I heard a quiet beep that repeated every eight seconds… then longer in between beeps. I left it plugged in overnight to charge but now hear a full quiet click when I try to start - otherwise completely dead. I think I did everything right in putting it back together, but no dice.
Any thoughts or suggestions? Could I have damaged the ram somehow??