Exynos Usb Device4000 Hot -

lsusb

Exynos SoCs, especially older ones like the 4412 (Galaxy S3) or 5422 (Odroid XU4), are power-hungry when they enter USB download mode. Unlike normal operation, download mode may bypass power management ICs, drawing current directly from the USB VBUS line. If your USB port or hub cannot supply stable 5V at 500mA–1A, the device resets mid-communication, triggering a “hot” event. exynos usb device4000 hot

| Cause | Mechanism | Observable Symptoms | |-------|-----------|----------------------| | High-current VBUS | Faulty charger or sinking >1.5A over VBUS for extended time | Connector pin 1 (VBUS) >55°C, PMIC overcurrent alarm | | PHY impedance mismatch | Degraded PCB trace or connector corrosion → reflected power → increased PHY bias current | SoC hot spot near USB region, packet CRC errors | | Continuous SuperSpeed operation | Exynos USB 3.0 PHY in P3 (U0) state for hours without LPM (Link Power Management) | Temperature rise from 30°C to 65°C within 15 mins | | Driver lockup | Kernel USB driver enters infinite polling loop → DMA engine stuck in active state → PHY never sleeps | usb 4-4000: reset high-speed USB device repeated every 2s | | Overvoltage on DP/DM | Moisture or short on USB data lines feeding 5V back into PHY's 3.3V domain | Burnt smell, charred resistor near USBLC6-2 protection IC | lsusb Exynos SoCs, especially older ones like the