Secret Codes On Oppo A9 2020 Upd |verified| — How To Use

To use secret codes on your OPPO A9 2020 Phone (Dialer) app and type the code exactly as shown

• Power off → Press Volume Down + Power → Choose “Test Mode” or “Manual Test”.

1. Add a trailing star or hash: Some codes require *# at the end, e.g., *#899#*#.
2. Use an alternate dialer: Download "MTK Engineer Mode" app from Play Store (requires no root for basic tests).
3. Check for carrier restrictions: Codes like *#*#4636#*#* are often blocked by Verizon or Jio. Use offline mode.
4. Factory reset (last resort): Rarely, corrupt system UI files break MMI interpretation. Reset from Settings → Additional Settings → Backup & Reset.

*#*#426#*#* – FCM Diagnostics: Provides information on Google Play Services connection events. how to use secret codes on oppo a9 2020 upd