Inverter Display Not Working? Fix a Blank or Dead LCD Screen

Key Takeaways

• A blank or dead inverter display most often points to a lack of power reaching the unit or the display itself.
• Always start by checking battery voltage and all external power connections, including AC, DC, and PV breakers.
• Before touching any internal components, ensure all power sources are disconnected to prevent electric shock.
• If basic power and connection checks do not restore the display, or if you suspect internal damage, contact a qualified technician.

My Inverter Display is Blank or Dead. What's Wrong?

A blank or dead inverter display typically means the inverter is not receiving sufficient power to operate its display, or there's an internal fault preventing the display from activating. The most common causes include critically low battery voltage, disconnected power sources (PV, grid, battery), tripped breakers, or internal component failures.

Diagnosis

Follow these steps to diagnose why your inverter display is blank or dead. Always prioritize safety by disconnecting power sources before inspecting connections.

Step 1: Check All Power Sources and Breakers

Ensure that all power inputs to your inverter are active and correctly connected.

1. Verify AC Grid Connection: Check your main AC breaker and any dedicated AC input breakers for the inverter. Ensure they are in the "ON" position.

• • For Growatt SPF 3500 ES / SPF 5000 ES inverters, a separate AC breaker is recommended between the inverter and AC input power source. The recommended spec is 40A for SPF 3500 ES and 50A for SPF 5000 ES.
  • For Axpert VM III inverters, the recommended AC breaker is 16A for 1.5KW, 32A for 3KW, and 50A for 5KW models.
  • For Deye SUN-SG03LP1-EU models, a separate AC breaker between the inverter and grid is required, with a recommended size of 40A for 3.6/5/6KW models.
  • Solis S5-EH1P-L Series inverters require a grid OCPD of 25A for 3K/3.6K models, 32A for 4.6K/5K models, and 40A for 6K models.

2. Inspect PV Input: Check the DC switch or breaker for your PV array. Ensure it is "ON". If it's daytime, your PV panels should be generating voltage.

• • For Growatt SPF 3500 ES / SPF 5000 ES and Axpert VM III inverters, a separate DC circuit breaker between the inverter and PV modules should be installed.

3. Examine Battery Connection: Confirm that your battery bank is securely connected to the inverter and that any external battery breakers or disconnect switches are closed (ON).

• • For Growatt SPF 3500 ES / SPF 5000 ES inverters, a separate DC over-current protector or disconnect device between the battery and inverter is requested. The recommended breaker specification for a single SPF 3500 ES unit is 100A / 60VDC, and for a single SPF 5000 ES unit is 150A / 60VDC.
  • Axpert VM III has a 150A fuse for battery over-current protection.
  • Solis S5-EH1P-L Series inverters require a battery switch with a rated current greater than or equal to 80A for 3K~3.6K Models, and 125A for 4.6K~6K Models.
  • Deye SUN-SG03LP1-EU inverters also require a separate DC over-current protector or disconnect device between the battery and the inverter.

Step 2: Measure Battery Voltage

A common reason for a blank display is a battery voltage that is too low for the inverter to initiate startup.

1. Use a Multimeter: Carefully measure the voltage directly at your battery terminals.
2. Compare to Minimums: Check your inverter's manual for the minimum "cold start" or "power-on" voltage.

• • For Growatt SPF 3500 ES / SPF 5000 ES in Lead-Acid Mode, the cold start voltage is 46.0Vdc. For Li Mode, the cold start SOC is Default 30%, which is Low DC Cut-off SOC +10%.
  • For Axpert VM III 1.5KW/3KW models, the cold start voltage is 23.0Vdc. For Axpert VM III 5KW models, it is 46.0Vdc.
  • If the battery voltage is far too low, such as below 1.4V/Cell for Axpert VM III or Growatt SPF 3500 ES / SPF 5000 ES, the unit may show no indication at all.

3. Recharge or Replace: If the battery voltage is below the minimum required, attempt to charge it using an external charger if possible, or consider if the battery needs replacement.

Step 3: Check for Loose Display Connections (Solis Specific)

Some inverters, like the Solis S5-EH1P-L Series, can have issues with internal display cabling.

1. Solis S5-EH1P-L Series: If all LEDs are off, the manual indicates that an "LED ribbon cable came loose during transport" could be a cause.
2. Safety Warning: Opening the inverter enclosure should only be done by qualified personnel. Risk of electric shock from energy stored in capacitors of the Inverter, do not remove cover for 5 minutes after disconnection from the utility grid and the PV input. Warranty may be voided if the cover is removed without authorization.

Step 4: Re-attempt Power-On Sequence

After checking connections and voltage, try the recommended power-on sequence for your inverter.

• Growatt SPF 3500 ES / SPF 5000 ES: "Once the unit has been properly installed and the batteries are connected well, simply press On/Off switch (located on the button of the case) to turn on the unit."
• Axpert VM III: "Once the unit has been properly installed and the batteries are connected well, simply press On/Off switch (located on the display panel) to turn on the unit."
• Deye SUN-SG03LP1-EU: "Once the unit has been properly installed and the baeries are connected well, simply press On/Off buon(located on the le side of the case) to turn on the unit." Note that for Deye, "When system without baery connected, but connect with either PV or grid, and ON/OFF buon is switched off, LCD will sll light up(Display will show OFF), In this condion, when switch on ON/OFF buon and select NO baery, system can sll work."
• Fox ESS H1(G2)/AC1(G2): After ensuring all wiring is complete and breakers are on, "Enter the settings page, default password is ‘0000’, select START / STOP and set it to start."
• Solis S5-EH1P-L Series: The startup sequence involves:

1. 1. Measuring DC voltage of PV strings and battery, ensuring polarity is correct.
   2. Measuring AC voltage and frequency, ensuring they are within local standard.
   3. Switching on the external AC breaker to power on the LCD of the inverter.
   4. Switching on the inverter DC switch.
   5. Switching on battery breaker.

Cause and Fix Table

Power Supply Checks for a Dead Display

A blank display is often a symptom of the inverter not receiving power. This section details how to check the power flow.

Battery-Side Checks:

1. Battery Voltage: As noted in the diagnosis, critically low battery voltage is a primary cause. Ensure your battery voltage meets the minimum cold start requirements for your inverter model. For example, a Growatt SPF 3500 ES / SPF 5000 ES in Lead-Acid Mode needs 46.0Vdc to cold start.
2. Battery Connections: Visually inspect battery cables for corrosion, looseness, or damage. Tighten any loose terminals.
3. Battery Breaker/Fuse: Check any inline DC breakers or fuses between the battery and the inverter. For Axpert VM III, a 150A fuse is provided as over-current protection for the battery supply. Ensure it is not tripped or blown.

Inverter-Side Checks:

1. DC Input from PV: If your inverter relies on PV to start or operate the display, ensure the PV input DC breaker is on and that PV voltage is present. Remember that "PV modules are dangerous when exposed to sunshine" and "installer should cover the PV modules by opaque materials" when working on them during the daytime.
2. AC Input from Grid: Verify that the AC input breaker is on and that grid power is available. An inverter like the Deye SUN-SG03LP1-EU can light up its LCD even without a battery if PV or grid is connected.
3. Inverter's Main Power Switch: Ensure the inverter's main ON/OFF switch is in the "ON" position.

If these checks do not resolve the blank display, the issue may be internal to the inverter or its display module.

Safety: Working with Inverters

Working with solar inverters involves significant electrical hazards. Always follow these safety guidelines:

• Disconnect All Power: "To reduce risk of electric shock, disconnect all wirings before attempting any maintenance or cleaning. Turning off the unit will not reduce this risk." This includes AC grid, PV array, and battery bank.
• Wait for Capacitor Discharge: After disconnecting all power sources, "Do not touch any inner live parts until 5 minutes after disconnection from the utility grid and the PV input" for Solis S5-EH1P-L Series inverters. Fox ESS H1(G2)/AC1(G2) inverters also warn that "some components can retain charge sufficient to create a shock hazard."
• Qualified Personnel Only: "All operations including transport, installation, start-up and maintenance, must be carried out by qualified, trained personnel" for Fox ESS H1(G2)/AC1(G2) inverters. "Only qualified personnel can install this device with battery" for Axpert VM III and Deye SUN-SG03LP1-EU.
• Wear PPE: "Use personal protective equipment, including gloves and eye protection during the installation" for Fox ESS H1(G2)/AC1(G2) inverters. Solis S5-EH1P-L Series states, "Operator must put on the technicians’ gloves during the whole process in case of any electrical hazards."
• No Disassembly: "Do not disassemble the unit. Take it to a qualified service center when service or repair is required. Incorrect re-assembly may result in a risk of electric shock or fire" (Growatt SPF 3500 ES / SPF 5000 ES, Axpert VM III, Deye SUN-SG03LP1-EU). "There is no user serviceable parts inside, refer servicing to qualified and accredited service technicians" for Solis S5-EH1P-L Series.
• Correct Polarity: "Before making the final DC connection or closing DC breaker/disconnector, be sure positive (+) must be connected to positive (+) and negative (-) must be connected to negative (-)" (Growatt SPF 3500 ES / SPF 5000 ES, Axpert VM III, Deye SUN-SG03LP1-EU). "Reverse polarity connecon on baery will damage the inverter" for Deye SUN-SG03LP1-EU.

When to Call a Technician Instead

While basic troubleshooting can resolve many issues, some problems require professional intervention. You should call a qualified technician if:

• Basic checks fail: You have verified all external power connections, battery voltage, and breakers, but the display remains blank.
• Internal fuse tripped: If you suspect the internal 150A fuse for battery over-current protection has blown, as mentioned for Axpert VM III, this requires opening the unit, which should only be done by qualified personnel.
• Suspected internal fault: Issues like "Abnormal control board functionality" or "Firmware update interrupted" (Solis S5-EH1P-L Series) are beyond DIY repair.
• Warranty concerns: Opening the inverter enclosure without authorization may void your warranty. For Solis S5-EH1P-L Series, "Warranty may be voided if the cover is removed without authorization."
• Safety risks: If you are unsure about any step or uncomfortable working with high voltages, do not proceed. "Only qualified service persons are able to service this device" (Axpert VM III).

For further assistance with inverter issues, you may find our guide on inverter will not turn on at all (dead unit) helpful, or if you hear unusual sounds, refer to what a clicking transfer relay means.