You will encounter many challenging objectives in Signalis, some of which may take quite a bit of thinking to figure out. One such objective you will face during one of the early stages of the game is to unlock the Classroom safe containing the Classroom Key. If you are having trouble with this, here is how to unlock the safe with its code to get the Classroom Key.
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How to unlock the 4b Classroom safe
Once you go to the second level after getting out of the Penrose ship by getting the Airlock Key, you will end up in a new location. You will need to unlock the 4b Classroom safe to acquire the Classroom Key. You must follow a few steps and go through different rooms to get the Classroom safe code.
Step 1: Get the Protector Key
From the starting location, head toward the reception and pick up the keycard from there. Now go to the main Corridor area and head straight to the small Corridor. Go to the room on the right side with a red terminal to save the game, and then go to the Corridor on the right. Head straight to the Aula room, and on a seat on the right, you will find the Protector Key.
Step 2: Get the Aperture Card
Once you have the Protector Key, head back to the main Corridor and unlock the Observation Room with the key. Pull out the second drawer in the room, and loot the gun and the Aperture Card. Equip the gun and head toward the Library from the left Corridor. Be careful on your way, as you will encounter one enemy.
Step 3: Get the password and unlock 4b Classroom safe
In the Library, use your Aperture Card on a small blue machine. The machine will read instructions and the password to unlock the safe in the Classroom. Now head to the Classroom by going left from the left Corridor. Interact with the safe and enter the code “204512”. Tap on the enter key and rotate the dial to unlock the safe. Once it opens, collect the Classroom Key from the inside.
