Forcing a phone into a pure BROM environment requires absolute timing precision.
Modern MTK chips use SLA (Serial Link Authentication) or DAA (Download Agent Authentication). If these are active and you haven't used a Bypass Utility , the BROM protocol will reject the connection attempt. brom protocol error check device environment
Plug the USB cable directly into the computer motherboard. Avoid front-panel ports, external USB hubs, or extension cables. Forcing a phone into a pure BROM environment
Last updated: 2025-09-20 Applies to: MediaTek BROM v5.1628 and later external USB hubs
If you want, I can:
Use tweezers to bridge this test point to the metal shield (GND) of the phone.