To flash the Samsung GT-E1207Y, you use a .pac file (the stock firmware) in conjunction with the SPD Upgrade Tool (also known as the ResearchDownload tool). This process is necessary for resolving software issues such as boot loops, "dead" phones, or sim locks. Prerequisites

Hold the Boot Key (typically the OK/Center button or Volume buttons) while connecting it to the PC via USB.

macOS / Linux

# Check system proxy PAC
scutil --proxy | grep ProxyAutoConfigURL
SPD Upgrade Tool: Also known as SPD Flash Tool or Research Download tool, this is used to load and install the PAC file onto the phone.