shakeel ahmad

It could be excessive bias (measured current at start-up when the current should be zero) from one or more of four current sensors:
output (load) current (there is a current transformer, it looks a bit like an audio transformer) inverter current (an LEM hall effect sensor I believe) output current sharing sensor (might be on the paralleling board? You could try removing that temporarily if you have one) the DC2DC current sensor. I believe that this is something unique to models with the 450 V max MPPTs, so I don't know anything about them. Unless you have an unusual load which has asymmetrical current (hair dryer on half power?), it doesn't look like something you can repair yourself. Perhaps attempt to demagnetise the CT or LEM, but that's about it.
Failing any of the above, it looks like you'll have to get it repaired or replaced under warranty, and I'd say it would be a main-board replacement. This is the most expensive part of the inverter-charger. It sounds like it's brand new (two days of service?), so unless you have any nasty loads, it looks like you should be able to get a warranty replacement. Unfortunately, with high demand and the COVID-19 situation, it may take some time to get resolved.

Yes, way too long I thought, was sitting reading the manual to try see why when suddenly it turned on by itself (I had of course turned the switch on after powering up). When the AC eventually turned on the battery had reached 52V (battery is a 16 cell LFP, with charge cut-off set to 56V.) so I wondered if it wasn't the recovery voltage set to that.

If I may here's the photo of the caps from the Axpert Repair thread hopefully saving anyone else in the same boat having to look for it in that (long) thread.
As a minimum replace C79 and C78 (1000uF 16V electrolytic) - (ref Coulomb & BritishRacingGreen).

Here is the chopper DC side legs picture, can that be the reason for heating of the mosfets

Hi,
I got this firmware (50.81) from Sorotec for REVO VM II Pro 3.5 and 5.5Kw inverters and I think it may be useful for someone.
The changes include reducing the PV normal operating voltage from 120 to 60 volts; adding a Lithium battery in battery type and other settings that I didn't get the chance to go through.
VMII-PRO-05150-08-S1-1.hex

Found the culprit, there is a short on the wifi board, its not working as well, short circuit on capacitor C9, i disconnected the wifi board and the
display is back on. Will replace the capacitor or wifi board and update.

The inverter is working now.. thanks to shakeel ahmad's help.. inverter, AC charging, AC bypass, PV charging battery-inverter and PV-inverter work now.. when I was reassembling everything back in the case, I forgot to connect one 4pin cable to the MPPT board, but shakeel ahmad found where to connect it
I'm not sure what was the problem in the beginning .. I did found a lizard's tail 🦎 under the main PCB and some dead bugs 🐛🐞 around PV connections 🤣 .. but I didn't actually do any 'repair'.. I guess the lizard and bugs made a short somewhere 🤔
I didn't have enough PV panels or batteries for testing so shakeel ahmad suggested to make a bridge rectifier with a capacitor from 230V AC to DC and use it for PV input.. Also, I used an electric scooter battery for battery input and everything seems to be working correctly now

it is just screen dead issue

Finally, my account works.
I've tried the 60.95, the fans become so quiet and SLOW with minor speed changes when charging and on higher load; due to the hot weather now in Syria, I've checked the fans and the blown air is so hot and I didn't feel it's fine. I flashed back the 60.89, the fans speed is a little bit higher but it's more reasnoble in hot climate places and speed change is noticable.