China phone software repair like Read phone info, Flash, Unlock, Re-lock, Code reset/Unlock etc, and some time need press boot key for USB enable software repair supported flash chip/IC's phone. It's defend on manufacture, models Flash ic's Example: Walton, Micromax, Symphony, Karbon, Qmobile and more. and there manufactures several model.
Were noted below boot key suggestion may work for around all chines MTK, SPD, MStar, Coolsand chip series phone. Make sure use correct cable/Jig then try boot key. by one after one. Make sure even only one key work for boot. So try below boot key use one key step after fail then try next boot key.
Boot Keys
1. Power button
2. Home/Menu key
3. Call key,
4. Camera button (when camera button on phone)
5. 5 key
6. * key
7. # key
2. Home/Menu key
3. Call key,
4. Camera button (when camera button on phone)
5. 5 key
6. * key
7. # key
Example: you want to read info, click (read info) button then release boot key.