I have HW errors too. But only at one chain. About 2000 HW per 12 hours. How can I resolve this problem?

Frequency 450M, chips temperature is 69, 67 and 68. Hashrate now is about 15 GH/s. I was downspeed my miner but HW on one chain continue to be.

May be I should write to bitmain support? WHat do you think?

By the way, what is HW errors? All chips on all 3 chains are Ok.