If your OnePlus One won’t turn on but only vibrates

Note to self: If your OnePlus One smartphone won’t turn on but only vibrates for a short time when you press the power button, that probably means the battery is dead. If it has already been on the charger for some time, make sure that you didn’t plug the charging cable upside down into the charger (it fits both ways but only one way works). If that isn’t the problem, try a different cable and/or charger.