Multiplus 12/3000/120 not responsive

Hello.

I have bought the second-hand unit Multiplus 12/3000/120-16 on eBay. It was sold as not tested so for spares or repair.

I tried to switch it on, but no LED blinks, no reaction. Looks like dead.

DIP switches - all in the off position.

Remote Control - the wire is connected to the 1 & 2 terminals.

The voltage on DC inputs with a battery connected is OK - 12.8 in my case.

The voltage on AC-IN i OK, (230), and I hear a bit of transformer buzzing, but with no battery connected I see no voltage on DC terminals (it should charge the capacitors as on my other Quattro, so something is wrong).

There is no voltage on either AC Out 1 or AC Out 2.

I was not able to connect via MK2 adapter to VEConfigure/VEFlash etc.

Here is a short video.

https://www.youtube.com/watch?v=PJ-frY08j3s

Visually everything looks fine.

Does anybody have such issues in the past?

Is there anything else I can do myself to realize why it does not switch on before looking around for service shops?

Thank you.