The first boot takes 5–10 minutes. Do not interrupt it.
For the tech-savvy user, there is a solution that can breathe new life into this aging device: . custom rom samsung a40
Open Odin on your PC. Put the twrp_a40.tar file in the "AP" slot. Uncheck "Auto Reboot". Flash it. Immediately reboot to recovery using Volume Down + Power. The first boot takes 5–10 minutes
The Samsung A40 has a decent development community, primarily on . As of late 2023/early 2024, here are the most popular and stable ROMs available: Open Odin on your PC
Exynos chips are notorious for aggressive background management, but also for inefficiency. Custom kernels and ROMs optimized for the A40 can drastically improve battery drain during idle time (deep sleep).
Released in 2019, the Samsung Galaxy A40 was a standout in the mid-range market. It offered a Super AMOLED screen, a compact form factor, and a respectable Exynos 7904 chipset. However, as technology moves at a breakneck pace, official software support for the A40 has waned. If you are holding onto this device, you may have noticed it becoming sluggish, or perhaps you are stuck on an older version of Android with the heavily skinned One UI.
Installing a ROM on the A40 follows a strict sequence to avoid "bricking" the device. Core Prerequisites SAMSUNG GALAXY A40 – How to Install Custom ROM