Chevrolet MyLink - Development Mode

From: https://sourceforge.net/p/mylink-startup-screens/wiki/Custom%20Mylink%20Startup%20Screens/

Custom Mylink Startup Screens

ONLY KNOWN TO WORK ON 2012-2015 Chevy Mylink AT YOUR OWN RISK
In theory your could potentially brick your MyLink doing this, everything you do once you enter development mode you accept all responsibility for your actions. It has happened to a few and all were covered under warranty, just don't go telling them what you did. You are on your own if you brick your unit.

Enable Development Mode

1. Turn car to ON postiion
2. On Mylink
3. Click Home
4. Tap upper left hand corner 10 times (I usually just hit it until develpment mode shows up)
5. Enter 20110827
6. Tap Submit (it should not actually do anything on that screen)
7. Tap Back
8. Tap Settings
9. Scroll down 3 times
10. Tap Develpment mode (if there is no development mode then you entered the code wrong go back to step 4)

Back up Factory Animation Screens

1. Enable Development Mode (look above)
2. Scroll down 2 times
3. Tap Explorer Mode
4. Insert USB Flash Drive
5. Tap My Device (top left hand corner)
6. Tap NORDATA
7. Tap and drag over Startup_ani_1.avi & Startup_ani_2.avi
8. Tap Edit (top left hand corner)
9. Tap Copy
10. Tap <- Back arrow all the way back to the my device (top middle)
11. Tap MD (this is your flash drive)
12. Tap Edit
13. Tap Paste
14. Do Restart Sequence From Explorer Mode

Note 1: You'll want to save those files someplace safe so you can always go back (I have created a folder on my flashdrive with them in it, and each individual custom screen I download I put in a seperate folder because they all have the same file name.)
Note 2: We have saved the Factory Animations in the files section just in case.

Restart Sequence From Explorer Mode

1. Tap Start
2. Tap Suspend
3. Turn car off
4. Take out key
5. Open door
6. Close door
7. Using Remote Lock Twice
8. Wait 30-40 Seconds
9. Using Remote Unlock Car (if you don't do this step the alarm will go off)
10. Turn Car to on Position
11. You should now be back to normal mylink

Adding Custom Startup_ani_1.avi to Mylink:

AT YOUR OWN RISK
1. Download the custome start screen from the files section.
2. Make sure it is names "Startup_ani_1.avi" (without quotes")
3. Copy it onto a USB flash drive
4. Enable Development Mode
5. Scroll down 2 times
6. Tap Explorer Mode
7. Insert USB Flash Drive
8. Tap My Device (top left hand corner)
9. Tap MD (this is your flash drive)
10. Go to the file you wish to be your start screen named Startup_ani_1.avi
11. Tap it 1 time
12. Tap edit (top left hand corner)
13. Tap Copy
14. Tap <- Back arrow all the way back to the my device (top middle)
15. Tap NORDATA
16. Tap Edit
17. Tap Paste
18. A popup will come up click Yes To All (its asking if you want to replace the file)
19. let it finish copying the file
20. Click start
21. Click Suspense
22. Do Restart Sequence (look above)
23. You should now see your startup animation if you did the above steps correctly.
Note 1: If the file isn't compatible or corrupt for whatever reason, you will see the ghost mylink screen until mylink loads.
Note 2: If the mylink remains on the ghost image and doesn't load mylink, redo the restart sequence or walk away for a few minutes and then come back. The one time this happened it loaded when I came back to the car.
Note 3: If the mylink boot loops as in shows the ghost screen might show the startup animation, and then loops over and over, you have successfully bricked your mylink.
Note 4: if mylink is black or white or doesn't come on at all, you have bricked your mylink.
Note 5: I don't know of anyone that has bricked the mylink just from playing with startup animations, the brick I have seen was due to trying to enable mirrorlink using the russian youtube videos.
If you BRICK your mylink, I hope your warranty is still intact, mylinks aren't crazy expensive on ebay, but I wouldn't want to have to buy a new one, and whatever you do don't tell them what you were doing, just tell them it quit working or it started doing this...