If the progress bar stops for more than 10 minutes, the connection was likely dropped. Do not cycle the main power yet. Check the cable tightness, restart the software, and try clicking start again. If you must cycle power on a half-flashed unit, it may enter a boot loop, requiring a recovery flash. Inverter Shows Error 09 (Bus Soft Start Fail) Post-Update
If you are looking to fix a specific error or optimize your system settings, tell me your and current firmware version so I can guide you to the right solution. Share public link
Completely close the WatchPower app/software from the taskbar, as it can block the COM port.
Updating the firmware on popular Easun models—such as the , SML-II/III , and SPH series—requires a methodical approach. Attempting to flash the wrong firmware can result in a "bricked" inverter, so it is critical to know exactly what you are doing. easun firmware update
Do not mix up firmware meant for high-voltage MPPT models (e.g., 450VDC PV input) with low-voltage MPPT models (e.g., 150VDC PV input).
Even with careful preparation, issues can arise. Here are solutions to the most common problems:
: Most modern laptops require this to bridge the serial cable to a USB port. If the progress bar stops for more than
If the cable was bumped mid-update, the inverter may display a blank screen and refuse to turn on.
: Check your current version on the inverter LCD or through the manual to ensure compatibility. Power Source
Turn the inverter back on. (Note: Only power up the inverter, keep solar array and battery connected, but do not turn on AC output/loads). Step 4: Flashing the Firmware Open the flashing software on your PC (e.g., Reflash Tool ). If you must cycle power on a half-flashed
Once the software indicates a successful update, restart the inverter. Use the software to check that the new version number is correctly displayed. 4. Troubleshooting
Firmware acts as the operating system for your inverter. Manufacturers release updates periodically to address field issues and improve hardware performance.
A: Yes, if the shop has a JTAG programmer and can source the original EEPROM dump. Cost usually exceeds the value of the inverter ($100-$200). Buy a new control board instead.
Some of the most common motivations include: