I started looking closely at the supplied connectors and saw one more black wire pin almost out of its connector. I pushed it back and connected again and for the first time I saw the unit booting. The booting did not finish though - it is now just black screen and I did not see it doing that again. I assume it is in standby now.
A new set of cables is sent to my place to fix my current issue of the G3 (ACC red wire) fell out of its connector and I don't know where to put it back. I expect this to be the wire which wakes the head unit up from standby on ignition.
My experience so far is bad quality of supplied connectors (pins pushed out of them on insert) because I don't have this issue when connecting the OEM head unit.
I hope once everything is connected properly there will be no issues.