How to diagnosis Ubox

Well, unfortunately, your ubox stopped working, we are very sorry for it, let’s try to figure out what’s happened to ubox, then we can decide what to do next. In general, the malfunctions of ubox can be these categories:

1. MOSFETS broken
2. VESC MCU bricked, or dead.
3. VESC bootloader lost.
4. VESC firmware problem, wrong or disintegrated firmware.
5. Internal receiver and light/horn malfunctioned.
6. Internal Bluetooth malfunctioned.

Let's discuss them one by one.

MOSFETS broken

Symptom: Surge current on battery wire, or huge sparking when plugged in battery.motor stopped working, cogging. Inspect： Plug off battery, then use a multimeter, set multimeter to on/off test mode.

1. .easure the on/off state between positive / negative (+/-) battery in wires, if multimeter report on continuously, some fets may have been broken.
2. .Measure the on/off state between positive (+) battery and each phase wire, if multimeter report on continuously, the fet you are measuring may have broken.
3. .Measure the on/off state between negative (-) battery and each phase wire, if multimeter report on continuously, the fet you are measuring may have broken.

Video link

ESC MCU bricked or dead

Symptom:

VESC status LED, green and red LEDs are dead, no sign of any activity.

Inspect：

When turn on ubox, use a multimeter, set multimeter to DC voltage mode.

Picture of VCC GND on the panel:

picture

Measure the voltage between VCC and GND, if it is still about 3.3V(ubox V1) or 3.44V(ubox V2), perhaps the MCU is bricked, not dead. For bricked MCU, we have wrote a blog for re-flash the MCU via SWD port, blog link.

If it is near 0V, then turn off ubox, measure the resistance between VCC and GND, if it is near 0 ohm, the MCU may have dead.

VESC bootloader lost.

Symptom:

Inspect：