Does ASRock Intel ARC B580 Steel Legend need both power connections?

Got new card and put into computer. It struggles but I can see Bios setup but if it tries to boot to windows all I get is horizontal lines. I tried HDMI and Display port. I suspect card is bad. But I figured one power connection to card would not cause card to malfunction.

Its a more high strung [ higher base a/o boost ] build, compared to reference / LE
Certainty, them intermittent spikes, barrel on past [*just enough] (1)8pin + PCIE slot supply

1000 watt pwr supply two power connections to card. Yup bad card.