I have done some improvements:
1) Made extended power connector with 3x2.5mm cable.
2) Switched it to stabilized supply
3) Connected it with direct internet line from main router
So, I don't know, what was cured, but now asic works great.
Additionally, I can see power consumption now.
Performance mode:
Miner consumption: 2 389.6 W
Sorry guys, it was router

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