vault 75 is discovered to be no different, and it will be up to the sole survivor to discover its sinister secrets. Vault 75 (quest) is a quest that can be obtained in the commonwealth in fallout 4. this may be caused by a misc quest pointing to the chems stash in the vault. bugs it is possible that the quest does not trigger upon entering vault 75, therefore causing the key cards not to spawn and making the science bobblehead unobtainable.

after exiting, turn right, then keep going in that direction until encountering a door to the lab on the right hand side marked security that needs an access card to be opened. in the basement of the malden middle school, go through the vault door and enter the elevator going down. Vault 75 is a side quest in fallout 4 which is triggered when exploring malden middle school.