While standard battery menus hide state-of-health data, entering the engineering portal lets you check raw battery voltage and charge temperature. This helps you determine if a fast-draining battery stems from a hardware chemical decline or from background software processes. ⚠️ Safety Precautions and Update Notice Oppo A9 2020 updates
⚠️ Secret codes give access to system-level tests. Do not change values in "Engineering Mode" or "Device Test" unless you know exactly what you are doing. Incorrect settings can affect your phone's performance. how to use secret codes on oppo a9 2020 upd
The process is identical to older Android phones: Do not change values in "Engineering Mode" or
Do not enter codes from untrusted sources, as some can trigger a factory reset ( *#*#7780#*#* ) without further warning. Before you start typing in codes, please keep
Before you start typing in codes, please keep these important points in mind to protect your phone and your data: