First, check if the battery's charge didn't run out. If it did, plug the charger into the laptop. If the fan was running loud and the laptop was hot, then too many programs were running. On start-up, try running less programs and make sure there's good airflow to the fan. Otherwise, the fan could be worn out or broken. Go to the troubleshooting page for more details.
If you do not hear sound coming from the laptop, first check if the sound is muted or set to low on the laptop and application. If this is not the case, your speakers may be blown out. Check the troubleshooting page for more details.
If the laptop is connected to another monitor, it could be outputting the image to a secondary screen. Press FN+F7 to toggle between screens. If that does not work, it could be that the screen's cable ribbon is loose or the pixels are dead. Head the to troubleshooting page for more details.