GoodWe Internal Fault | Faisalabad, Lahore

GoodWe inverter shows an internal fault (Bus, IGBT, CPU, HCT or Internal Comm Loss)

Short answer

Many GoodWe codes, including F21 Internal Comm Loss, F30/F31 HCT checks, F36 and F81–F90 bus overvoltage, F69/F70 IGBT, F71 NTC and F72–F80 control faults, are internal. GoodWe's step for nearly all of them is: switch AC and DC off, wait five minutes, switch on; if it stays, contact service.

What you will see

An internal F-code and the inverter stops

Why it happens

Self-checks on the inverter's own circuits. A grid spike can trigger one once.

Diagram

What to do with internal codes

01Write down the exact code
02AC and DC off, wait 5 minutes
03Switch on
04Comes back?
05Call with code and serial

Examples:

F21F36F69F71F81–F90

GoodWe inverters using F-code numbering (DNS G4, SDT G3, ES Uniq, ET).

What you can check yourself

Write down the code
Restart once using our safe restart guide

What not to do

Do not restart repeatedly
Do not open the inverter

When to call us

Read fault history
Update firmware if advised (F33 flash errors)
Raise a GoodWe warranty case

Warranty cases

We collect logs and help raise GoodWe warranty cases from Faisalabad and Lahore.

Send us

the code, screenshots and serial number