Technical Diagnostic Search
High-Voltage Solar Overvoltage Lockout
Error ERR-304 triggers when open-circuit voltage (Voc) on the high-voltage PV port exceeds the hardware threshold of 150V DC (often exacerbated by low temperature coefficients), causing the MPPT controller to latch shut to protect internal DC bus capacitors and buck-boost MOSFETs.
BMS Communication Link Failure
Error 102 indicates an interruption or packet loss in the high-voltage serial/CAN bus communication between the inverter unit and the external LFP battery module. The main controller initiates safe shutdown of high-voltage DC contactors to prevent thermal runaway or unbalanced pack discharge.
Heated Bed Cable Fatigue
The mainboard firmware detected abnormal resistance variation or intermittent connectivity along the AC heated bed wiring harness, triggering an emergency thermal cutoff to prevent electrical shorting or fire hazards.
Corner Touch Unresponsiveness Fix
The Goodix/Synaptics touch IC firmware edge-suppression algorithm misclassifies valid corner tap events as accidental palm contact, exacerbated by outdated panel firmware or out-of-spec SPI polling rates.
Steer-by-Wire Redundant Actuator Fault
DIR_a436 indicates a loss of redundancy or communication divergence in the dual-motor Steer-by-Wire (SbW) front steering rack actuator. The primary drive inverter detected a resolver mismatch, 48V power distribution asymmetry, or CAN/Ethernet bus fault on the secondary steering motor channel.
A1 Heatbed Cable Damage
HMS_0300 triggers when the mainboard detects abnormal NTC thermistor resistance readings, open circuits, or thermal runaway risks caused by mechanical fatigue or internal wire fracture in the AC heatbed wiring harness.
Baseband SDX71M Firmware Panic
A kernel panic initiated by the Apple A18 Pro SoC due to an unrecoverable timeout or assertion failure in the Qualcomm Snapdragon X71M (SDX71M) baseband processor. The application processor triggers a watchdog restart when PCIe/UART link synchronization is lost with the cellular modem.
FlexiArm Side Brush Motor Stall
Error 104 indicates an overcurrent or stall condition detected on the Roborock FlexiArm mechanical deployment linkage or rotational side brush DC drive motor. Mainboard current-sensing shunts trigger shutdown when load exceeds safety thresholds.
Cell Overvoltage Imbalance Fault
Error ERR_BMS_301 triggers when the Battery Management System detects an individual LiFePO4 cell voltage exceeding the upper safety threshold (>= 3.65V to 3.75V) or an excessive inter-cell delta (> 100mV-150mV) during charging, disabling input charge FETs to prevent thermal runaway.
HV Contactor Opens Under Load
The Battery Management System (BMS) commanded high-voltage main contactors open during high current draw due to detected isolation breakdown, pyrofuse pre-trigger thresholds, or severe inverter DC-link voltage mismatch (>800V bus).