Stranger Things 3: The Game Guide will cover wholly on where and how to find the Cerebro Parts which will help complete the mission. This is the last objective of Chapter #1 which you have to do so with Dustin.
Stranger Things 3: The Game Cerebro Parts
You will need three parts to make the Cerebro start running again. These three parts are scattered around Weathertop and you will have to explore it a bit.
These parts are found in chests at certain locations and you will need the help of Dustin to hack open the chests.
A few chests are scattered at different locations but you do not need to look for all chests. Simply go to the western and southern chests and you will get the Cerebro Parts but beware of enemies.
The last part can be found in the centermost area of the forest which will be an open area. This part will be guarded by several enemies so take care of them first. After finding all the parts, just take them to the broken Cerebro and you will finish Chapter #1.