If the battery was deeply drained plug it into a known-good wall charger and leave it alone for a few hours, then do the 30–60 second power hold while it’s still plugged in. Also clean the charging port with a wooden toothpick and try a different cable; lint or a weak cable can stop it from charging. If it has a microSD card and remove it before trying the reset, since a flaky card can stall boot.
