I bought:

MSI Z270 SLI PLUS
6x GTX 1060 6GB (4 arrived so far)
Celeron G3930
4GB RAM
120GB SSD
2x 600+W psu (seasonic 620W atm, real ones not here)

Windows 10

I set everything up and started adding cards one by one, but they just will not show up, whatever i do.

Very often the machine will not even give me a picture after adding a second card.

I have 7 or so USB risers from a few years back and never used them.

I am virtually out of ideas.

Trying to add a card to any slot often results in no signal on HDMI or if i boot and get to bios, the card is simply not there when i look at "Board browser".

When i finally got 2 cards detected, the machine freezes after less than a minute of trying to mine.

This is frustrating as hell. Could all my risers be bad?