Warning What does this mean?

Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.

Deye Inverter F05/F06 — EEPROM Memory Errors Explained

F05 and F06 are internal memory faults: your Deye inverter failed to read (F05) or write (F06) its EEPROM — the small memory chip that stores its settings and operating data. When the inverter cannot trust its own stored data, it stops rather than run on corrupted settings. Deye’s official remedy is straightforward: restart the inverter, and if the fault is still there, contact your installer or Deye service.

What should I do first?

Two quick questions — we'll point you to the right starting point.

Is this code still showing on your inverter's display?

What this code means

Every modern inverter keeps critical information in non-volatile memory: grid protection settings, calibration data, energy counters, and configuration parameters. In Deye’s string inverters this memory is an EEPROM chip, and the control processor reads and writes it constantly during operation.

F05 means a read operation failed — the processor asked the memory for data and did not get a valid answer. F06 means a write operation failed — new data could not be stored reliably. Either way, the inverter is now in a position where it cannot be sure its settings are intact. Running a grid-connected power converter on suspect settings is not acceptable, so the safe response is to stop and flag the fault.

The encouraging part is that these faults are often one-off electronic glitches — a power dip, a burst of electrical noise, or a stray bit flip can corrupt a single memory transaction without any lasting damage. That is why Deye’s first and only homeowner step is a restart: if it was a glitch, the next read/write succeeds and the inverter carries on normally.

The less encouraging part is that a memory fault that survives a restart points to a real hardware problem: a worn-out EEPROM cell (these chips have a finite number of write cycles), a failing memory chip, or a fault in the control board around it. None of those are field-repairable by a homeowner. The good news is that the inverter diagnosed itself — it told you exactly which subsystem failed — so your installer starts the service call already knowing where to look.

What is this downtime costing you?

Rough estimate while your system isn't producing. Adjust the numbers to match your setup.

System size (kW) Peak sun hours / day Electricity rate ($/kWh)

–per day

–per week

–per 30 days

≈ – kWh of lost production per day.

Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.

Common causes

['A one-off electronic glitch — a brief power dip or burst of electrical noise corrupting a single memory transaction.', 'A worn-out EEPROM memory cell — flash memory has a finite number of write cycles, and years of operation can exhaust them.', 'Corrupted settings data after an interrupted firmware update or a sudden power loss mid-write.', 'A failing EEPROM chip or a fault in the control-board circuitry around it.', 'Unstable internal auxiliary power feeding the control electronics.']

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 1 done.

['Restart the inverter using its documented shutdown and startup sequence — switch off AC first, then DC, wait a few minutes, then switch back on in reverse order. This is Deye own first step.', 'After the restart, check the display: confirm the fault is gone and the inverter resumes normal operation.', 'Glance at the basic settings (date, time, grid standard) to make sure nothing looks scrambled.', 'Note whether the fault returns immediately, after some hours, or not at all — the pattern tells the technician whether it was a glitch or a dying chip.', 'If it returns, photograph the display showing the fault code and timestamp for your installer, and do not attempt firmware updates or factory resets on your own — updating a unit with a faulty memory chip can make things worse.']

Is your inverter still under warranty?

Before paying for a repair, check — your installer may fix this free.

Brand Year installed

Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.

When to call an electrician

If F05 or F06 survives a proper restart, call your installer or Deye service — that is exactly what Deye’s manual prescribes. A persistent memory fault almost always means the control board or the EEPROM itself needs professional diagnosis, and usually board-level repair or replacement. Do not keep power-cycling the unit in hopes it clears; repeated faults confirm the hardware diagnosis.

Frequently asked questions

What is EEPROM, in simple terms?

It is a tiny memory chip inside the inverter that remembers settings and data even when the power is off — like the inverter’s notebook. F05/F06 mean the inverter had trouble reading from or writing to that notebook.

Will I lose my generation data or settings?

Possibly some recent counters or settings could be affected, which is precisely why the inverter stops instead of running on suspect data. Your installer can verify and restore settings after the fault is resolved.

Is it safe to keep restarting the inverter to clear F05?

One proper restart is the documented step. If the fault keeps coming back, stop cycling power and call for service — the repetition itself is diagnostic information.

Could a firmware update fix this?

Only a technician should decide that. Updating firmware on a unit with a failing memory chip risks bricking it, so this call belongs to your installer or Deye service.

Need a professional?

This fault may need professional diagnosis. Contact a qualified solar electrician in your area.

Sources: meaning and troubleshooting verified against the manufacturer's documentation — Deye SUN-(3-10)K-G03 Grid-tied PV String Inverter User Manual (Ver 2.1, 2021-6), §10.1 Table 10.1 — F05 ‘Read the memory error’ (failure in reading memory/EEPROM), F06 ‘Write the memory error’ (failure in writing memory/EEPROM) (deyeinverter.com)