A failed repair can cause the phone to restart every few minutes. This usually requires a specific "Restart Fix" file or reflashing the stock firmware. Dead Boot:

Connecting the phone in "Brom" or "Preloader" mode (often by holding both volume buttons while plugging in the USB). MediaTek Tab:

, which uses a MediaTek chipset, the general workflow involves: Brom Mode:

Sometimes the process leads to a "Null IMEI" or "Unknown Baseband" status. Technicians fix this by flashing specific "Security Files" or "NV Data" backups. Restart Loops:

, have high-level security that prevents direct IMEI modification . To bypass this, technicians often have to downgrade the firmware