Unlock the Peacekeeper from start to finish.
If you haven't already, I encourage you to solve the Peacekeeper mystery.
It's a lot of fun and a game within a game.

You must unlock the Beginning, Omen, Conflict, Angel Sighting, and Belly of the Beast dog tags, as well as the Escalation skin, to complete the Peacekeeper quest. If you don't have these unlocked, you will keep dying in the mineshaft. Taking dog tags from enemy soldiers does NOT count.

The dog tags can be made on different days, it doesn't all have to be done at once.
You can complete all the dog tags in any order or unlock the Escalation skin, but everything must be completed before entering the mineshaft. The Escalation skin is for the M1917 MG, so if you don't have that weapon unlocked, you'll need to unlock it to have it for the mineshaft step. You can also borrow the weapon from a friend who has the Escalation skin equipped, so you can skip that step. You don't need to have the weapon equipped while solving other puzzles, just for the final step.

The Dog Tag Color Morse Code stations for beginners can be completed on different days. When you get the headphones and activate the Morse code, it will not change until you find the symbol, so you can take a break and come back to find the next symbol or decipher the next color. Once you have recorded the Morse code at the color station, you can immediately exit the game to decipher the message.

The Omen and Conflict Dog Tags and the Escalation Skin unlock MUST be completed in one playthrough.
The Morse Code in Albion (Escalation Skin) and Zeebrugge (Omen) must be deciphered during gameplay. If you leave the game before completing the Escalation Skin or Omen Tag, the Morse Code will change and you will have to start over. Solving the floor puzzle in Soissons (Conflict) must also be completed in one playthrough. If you leave the game at any point, you will have to start over.

Your Morse code results will be different (unless I say otherwise), but this is just a guide to how I solved my own codes.

To record the Morse code, I simply put my smartphone next to the gaming speaker and recorded a video of about 30 seconds. Then I uploaded the video to my computer and played it at 0.25x speed and wrote down all the dots and dashes. Some people have uploaded their videos to YouTube to slow down the video. Some people have used Audacity to decipher the Morse code for you instead of writing it down. Some people have used apps to decipher Morse code, but no idea how reliable these are. The clearer you can record the sound, the better the results.

If you are using a PC, you can also use video recording software to record Morse code instead of your smartphone. (I don't know if consoles have recording features that can help you with this.)

You can use any of the 9 original cards in the manual to find headphones.
Use Conquest mode to open the entire map. When selecting a map, make sure the player count is set to /"All/" to find empty servers. You can also try setting the server region to other continents if you can't find maps in your region. For this video, I rented a private server. You have to pay a small fee, but at least you can kick people who join.

It doesn’t matter whether this happens during a game or before the round.
It doesn't matter whether it is a DICE server or a private server, as long as the private server is not password protected.

Headphones appear randomly in certain locations where they appear, and sometimes not at all. Simply restart the map and try again if you can't find them. Use the BF1 Game Detectives Guide to find out where the headphones are and icons for each map.
If you die with the headphones, they will reappear where you found them.

***Please note that internet decryptors and other helpful puzzle solving apps may change since this video was made. For the Soissons Candle Light app, you can simply search the internet for /"BF1 Candle Solver/" or something similar to find an alternative.

Morse code translator I use:
https://morsecode.world/international/translator.html

These instructions will help you!
https://wiki.gamedetectives.net/index.php?titleBattlefield_1#River_Somme
https://wiki.bfee.co/index.php?titleBattlefield_1/A_Beginning
https://wiki.bfee.co/index.php?titleBattlefield_1/A_Conflict
https://wiki.bfee.co/index.php?titleBattlefield_1/An_Omen

If you have any questions, just ask!

Time stamp:
0:00 Start
0:30 White
2:05 Yellow
3:10 Blue
4:50 Green
6:20 Clear
8:44 Orange
10:55 Pink
12:35 Green
14:19 Cyan
14:42 Start
15:45 Escalation Skin
24:03 Omen
28:40 Conflict
37:15 Angel sighting
40:10 Belly of the Beast
42:10 Mine shaft
45:00 Peacekeeper

Subtitled Spanish

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