Just an update to my original problems.  I sent the inverter back to Voltacon who said they tested it and it worked fine with no remedial work required. No F11 fault but there was the default serial number still present.  They have sent it back to me and it operates fine, albeit with the incorrect serial.  I'm really not sure what they did, apparently nothing?  I don't know how putting the inverter in a box a shipping 100 miles fixes things but apparently it does.  Must have been a magic box.  I've now changed my installation to Sunsynk inverters and they work much better as a parallel setup compared to the Voltronic.

30 minutes ago, Tonypee said:

I don't know how putting the inverter in a box a shipping 100 miles fixes things but apparently it does.  Must have been a magic box. 

Or it got the right sort of "Good Vibrations"🎶 on the way out, and thank goodness that the goodness didn't get baddened on the way back 🙂.

The courier must have had the Beach Boys on the radio at full volume. 

I'd still like to know why the serial has gone. Voltronic sent me a set serial program but it failed to update. As long as it works it's not really a problem. 

4 hours ago, Tonypee said:

As long as it works it's not really a problem.

The problem may happen 60 powered days (1440 hours of operation) from when the serial number was lost. At that point, you may get fault code 90.

4 hours ago, Tonypee said:

Voltronic sent me a set serial program but it failed to update.

You have to issue an ATE1 command first; it should be in the instructions. Then ATE0 to resume normal operation. I hope I didn't get that backwards.

4 hours ago, Tonypee said:

I'd still like to know why the serial has gone.

I suspect that with any glitch in the EEPROM and it defaults to fixed values, including the 5535553... serial number. There are checksums to ensure that the data integrity is complete for half a dozen segments of the data.

i test all eeproms chips from same control board with problem: i can read data but i cand write, i try erase chip but data still there, chips are broken. i place new chip with data from bad chip, remake serial and inverter work very good. will see in 60-90 days if problem is. Also, monitoring software no report anymore "eeprom fault"!

5 hours ago, mihaigsm2003 said:

i place new chip with data from bad chip, remake serial and inverter work very good.

Interesting. I suppose it's possible that only the write circuitry has failed, in which case copying the old data to the new chip should work fine.

It just seems unlikely to me, but I have little experience with these chips.

On 2023/08/12 at 6:33 PM, Coulomb said:

  On 2023/08/12 at 1:42 PM, Tonypee said:

Voltronic sent me a set serial program but it failed to update.

If memory damaget can't write serial number

Hi,

Thank you for share your experience. This really helped me.

I used a second, working inverter to get a working dump from it.

I'm sharing my dump from AXPERT MAX II 10K.

I've added the dump for the screen.

Good luck.

MAX II-10KW.zip

Edited September 29, 2025Sep 29 by ALEX_VA