This achievement is story-related.
When you land on Mahavid, take the elevator down, dispatching the Marauders and Brutes. Nothing to see here so move on, take a Medkit on the left and go for the door. Watch the scene. Inside the office is a Datapad worth 2500 creds, but nothing else. Another Datapad worth 1250 creds is on a bench, near the female Miner you can talk to. There is nothing else of interest here, so you can use the drone to repair the elevator and move on.
As soon as you exit the elevator upstairs, look on the bench on your left, behind some rocks, and you’ll find a hidden Datapad worth 1250 creds. In the Mineral Lab, a Datapad worth 1250 creds lays in the middle of some flower pots. Opposite is a Terminal on the wall worth 1250 creds as well.
At the end of the hallway is a blast door you can bypass. Do so and enter the room. A Datapad worth 1250 creds can be found next to the next door you need to bypass. Do so, and voilà. One Datapad that will unlock a cutscene and 2500 creds, and a SMG High-Velocity Barrel mod. You can now take the upper door to Sector 4, where for now you can just recover a Datapad worth 1250 creds in the little office, and the ID number we need to go get a hidden mod. Now backtrack to the Security Console and activate it.
After the scene, you get the file number required to progress the story, but first, let’s go get that mod. Do not follow your objective but unlock the Crew Quarters with your access code. You will find inside 2 Datapads (might wield some EXP for you), and another mod, some Pistol Ultralight Materials. Now go towards your objective and unlock the door there with the file number, and move on.
In the Medical Bay, examine the body on the left to get a scene. The next section is not timed, so you can actually turn around and get the Medkit. Then, move on.
Outside, dispatch a few Husks and continue. On your path, impossible to miss, will be a SMG Mass Pulse Recoil System mod. Grab it and progress towards a large area where a big fight will take place. Stay at the beginning because you need a cover in front of you, but also to your left. Nothing you can’t handle except 2 Banshees at the end, but you have a Blackstar all the way to the left. When the area is clear, cross it but do not enter the door yet. Instead, look on the right and you will find some grenades, a Medkit and a Pistol Cranial Trauma System mod. Now try to enter the door.
You will have to escort the little drone to 2 places while staying close to it. The first place is right next where you start, so it is not hard to reach, but be prepared for a good fight once you do. Expect a good amount of Ravagers, and when you reach the second point, exactly where the Blackstar was, a Banshee will appear, but she’s far, so nothing to worry about. Go back for the door.
After the scene and some chat, you will unlock the No Stone Unturned achievement.