Solar Inverter Not Turning On? What to Check

Updated June 2026 · Reviewed for technical accuracy · ~4 min read

A completely dark inverter, with no display and no error code, is unsettling, but the cause is often simple and safe to check: a switch that is off, a grid outage, or a flat battery. Here is what to look at, in order, before you call anyone.

First, work out what "dead" means

There is a difference between an inverter that is fully off (no lights, blank screen) and one that is on but idle (screen lit, just not producing). This guide is about a genuinely dark unit. If you do see a code, look it up instead, because the code tells you the exact issue.

The safe checks, in order

Switches and observation only Everything here is external. Do not open the inverter or touch any wiring.

Is there a grid outage? Many grid-tied inverters power down their display when the grid is gone. Check whether the rest of the house has power. If it is a load-shedding or a cut, the inverter will wake up when power returns. This often shows as F35 on Deye or Sunsynk once the screen is back.
Check the AC breaker. Find the breaker between the inverter and the home or grid and make sure it is on. Reset it if it tripped.
Check the DC isolator. The switch (often a rotary knob) between the panels and the inverter must be on for the unit to wake during the day.
Check the battery. On a hybrid system, a deeply discharged battery can leave the inverter without enough voltage to start, especially at night or after a cloudy spell. Once it charges from the sun, the inverter usually comes back. This relates to F56 (DC bus voltage low).
Check the battery's own switch. Many batteries have their own on/off button or breaker. If it is off or the battery went into protection, the inverter may not start.
Wait for daylight. A grid-tied, battery-less inverter is meant to be dark at night. If it lights up in the morning when the sun hits the panels, nothing is wrong.

When to call a professional

Bring in an installer if the grid is present, the breakers and isolators are all on, the battery is charged, and the inverter is still completely dark in good daylight. At that point it points to an internal power-supply or hardware issue that needs a qualified person. The same applies if you see or smell anything burnt, which is an emergency.

If a code appears

As soon as the screen comes back, it may show a fault code that explains what happened. That is good news, because the code points to the exact fix. Type your code on the home page to get the meaning and the steps, and see our guide on how to safely restart your inverter.

⚠️ Safety disclaimer. Solar inverters and batteries carry lethal voltage even when "off". This guide covers external checks only. Never open equipment or touch wiring or battery terminals unless you are qualified. When in doubt, call a licensed installer or electrician.