Try a different USB cable. Many microUSB cables are charge-only and lack data lines. Also test different USB ports on your computer, preferably USB 2.0 ports rather than USB 3.0.
The absolute best way to revive this device without a hardware box is using . c3520 flash loader 75 4 csc v02 citrus 218l better
: If the keys 1 and 2 are released a fraction of a second before the USB handshake finishes, the boot ROM exits flash mode. Keep both keys pressed until the progress bar advances past the initial configuration block. Try a different USB cable
The guide below details how the correct configuration solves common system errors and provides a step-by-step walkthrough to flash your device safely. Understanding the Components The absolute best way to revive this device
– Please clarify or correct the product name. For example, if you meant: