In Stranger Things 3 The Game one of the early quests once you’ve found Dustin is to get Cerebro back up and running. You’ll need to find three parts to fix the device, but you’ll have to explore Weathertop to do so. The three parts are located in different parts of the wooded area.
The first two parts you can find in chests. You’ll need to use Dustin’s hacking ability to open the chests that you find in Weathertop to access them. You can get all the pieces you need by heading west of the Cerebro device.
There are a few different chests in the area. Once is in the middle of the Weathertop forest. Two are in the southeast corner and one is far west. You’ll need to visit the western and southern chests to get two Cerebro parts. However, there will be enemies waiting for you. The last piece is located in the middle of the forest in a clearing that is being guarded. Kill the enemy and then take the parts back to Cerebro to make the call which will start Chapter 2.