Solar Inverter Not Turning On – Faults & Fixes

Solar Inverter Not Turning On – Common Faults & Troubleshooting Guide

A solar inverter is the heart of any solar power system. But sometimes users face the issue where the inverter does not turn on or shuts down unexpectedly. This problem is very common in residential and commercial setups.
In this article, we will go through the most common faults, their causes, and practical solutions.

 No Power Supply to the Inverter

Fault: The inverter receives no AC or DC input.
Solutions

• Check the DC solar input using a multimeter.

• Verify the AC mains supply (for hybrid inverters).

• Inspect the fuse or circuit breaker – replace if tripped.

•  2. Battery Connection or Low Voltage Issue

• Fault Low or dead battery voltage prevents the inverter from turning on.
  Solutions

• Ensure battery terminals are clean and tightly connected.

• Measure battery voltage with a multimeter (12V / 24V / 48V as per system).

• Recharge or replace the battery if the voltage is below the cut-off level.

• 3. Internal PCB / Fuse Failure

• Fault Internal fuse, MOSFET, or IGBT may be burnt.
  Solutions

• Open the inverter and check the main fuse.

• If the fuse keeps blowing, MOSFETs or IGBTs could be shorted.

• Replace faulty components or consult a qualified technician

•  4. Overheating & Cooling Fan Problems

• Fault The inverter goes into thermal protection mode and refuses to power on.
  Solutions

• Check if the cooling fan is spinning.

• Clean dust from the heat sink and ventilation slots.

• Reapply thermal paste or replace the cooling fan if necessary

• 5. Software / Firmware Errors

• Fault Display shows error codes or remains blank.
  Solutions

  • Refer to the inverter’s user manual for error codes.

  • Perform a firmware reset (if supported).

  • If the display remains off, check the microcontroller section

  • Quick Troubleshooting Circuit Diagram

  • Here’s a simple solar inverter connection diagram for better understanding

  
  
  
  
  

  Conclusion

If your solar inverter is not turning on, start with the basics:

• Check the power supply

• Verify the battery connections

• Inspect the fuse and PCB

Most problems are solved at this stage. However, if the issue is internal (PCB or firmware level), it’s recommended to get help from a professional technician

At Fault Store, we share detailed fault-finding guides, repair tips, and circuit diagrams

to help you fix your solar electronics effectively. Stay tuned for more posts on battery inverters, lithium systems, welding inverters, and electric bikes.